INTRODUCTION
The genus Boehmeria Jacq. belongs to the family Urticaceae Juss. (Gaudichaud, 1830; Weddell, 1856, 1869; Yahara, 1990; Wilmot-Dear and Friis, 2013). It occurs mostly in Northeast and Southeast Asia and includes approximately 47–120 species (Chen et al., 2003; Zhao et al., 2003; Wilmot-Dear and Friis, 2013; Liang et al. 2020). It is distinguished from related genera by the absence of stinging trichomes, presence of filiform stigmas, persistent stigmas during fruiting, persistent perianth on the achenes, scarious achenes, and absence of fleshy receptacles (Chen et al., 2003; Tateishi, 2006; Kim, 2018).
In terms of intrageneric classification, Blume (1857) initially divided 74 species of Boehmeria into six sections, i.e., Chamabainia, Duretia, Genuinae, Margarocapus, Tilocnide, and Urocnide, based on various morphological characteristics, such as the phyllotaxy, leaf texture, inflorescence, stipitate ovary, stigma, and achene. Weddell (1869) classified 47 species and 37 varieties into four groups based on the inflorescence shape and phyllotaxy. Satake (1936) classified 40 species, five varieties, and five forms from Japan (including Korea) into two subgenera, Duretia and Tilocnide, based on the phyllotaxy, trichomes on the abaxial leaf surface, and inflorescence. The subgenus Duretia was further divided into seven sections: Densiflorae, Longispicae, Pannosae, Sieboldianae, Spicatae, Splitgerbera, and Zollingerianae. Tateishi (2006) later supplemented the classification system of Satake (1936), recognizing 18 species and three varieties of Japanese Boehmeria, arranged into two subgenera and five sections based on the habit, stem color, phyllotaxy, leaf margin, presence of white trichomes on the abaxial surface, leaf texture, and shape and trichomes of achenes. Wang (1981a, 1981b) classified 32 species and 11 varieties of Chinese Boehmeria into five sections based on morphological characteristics. Moreover, Sect. Duretia was subdivided into four series, Densiflorae, Ingjiangenses, Longispicae, and Siamenses, according to the leaf shape, inflorescence shape, presence of fruit stipe, achene shape, and presence of wings.
Subsequently, Wang (2016) established a new series, Spicatae, within sect. Duretia. The series Spicatae is clearly distinguished from ser. Longispicae by having fewer trichomes, often reddish coloration, slender stems, small thin chartaceous leaves with sparse short trichomes or sub-glabrous surfaces, simple spicate inflorescences, and strigose or glabrous perianths in pistillate flowers. The classification systems for Boehmeria are largely based on East Asian taxa, particularly those from China and Japan, and traditional morphology-based systems continue to be adopted (Kang et al., 2008; Liao et al., 2009; Yu et al., 2015; Liang et al., 2020).
Taxonomic confusion within Korean Boehmeria persists, as there is substantial morphological variation, even within populations. Furthermore, the levels of morphological variation and differentiation among species have not been clearly determined (Lee, 1996a, 1996b; Lee, 2003; Lee, 2006; Liang, 2009; Chang et al., 2014; Kim, 2018; Hwang, 2020). Therefore, the objectives of this study were (1) to examine variation in established characteristics and to elucidate new diagnostic characteristics for 16 taxa of Korean Boehmeria (including four endemic and three previously unrecorded taxa); (2) to clarify the identity of ambiguous Korean endemic taxa, namely B. hirtella, B. nakaiana, B. quelpaertensis, and B. taquetii, as well as morphologically ambiguous taxa through comparative analyses; and (3) to evaluate the validity of existing classification systems and propose a revised system for Korean Boehmeria.
MATERIALS AND METHODS
The study focused on 16 taxa, including three previously unrecorded taxa in Korea. Materials were collected during the flowering and fruiting seasons from May 2016 to November 2022. Collected materials were made into herbarium vouchers, and some were preserved in 70% ethanol. All specimens used in the study were deposited in the Herbarium of Gyeongkuk National University (ANH). Additionally, type specimens were observed for accurate species identification. Various morphological characteristics were confirmed through the examination of images and specimens borrowed from domestic and foreign herbaria. The representative specimens observed are provided for each taxon, and all examined specimens are documented in Jo (2023). Distribution data for each taxon were generated based on the specimen data examined in this study. The scientific names of each taxon were reviewed in accordance with the Shenzhen Code (Turland et al., 2018). Jo et al. (2024), based on specialized references, newly reorganized and illustrated the trichomes of Korean Boehmeria. The present study adopts their treatment.
Observations and measurements of morphological characteristics were conducted through fieldwork, supplemented with analyses of both dried and liquid specimens. Quantitative characteristics of major parts were evaluated using a Vernier caliper (Digital Caliper, Brütsch/Rüegger Tools Ltd., Urdorf, Switzerland), and qualitative characteristics were evaluated under a stereomicroscope (SZH10, Olympus Corp., Tokyo, Japan); images were captured using a camera (IMTcamUSB3.0_ISP6.3, i-Solution, Burnaby, Canada).
To observe the micromorphological structure, materials preserved in 70% ethanol were cut into specific parts. Then, they were gradually dehydrated in 80–100% ethanol (30 min each). Impurities were removed using an ultrasonic cleaning bath (2510 EDTH, Branson, Danbury, CT, USA) before each solution substitution. Following dehydration, samples were dried using a critical point dryer (Leica EM CPD 300, Leica Microsystems, Wetzlar, Germany) with 18 cycles of liquid carbon dioxide substitution. They were then coated with gold (Au) for 65 s using a sputter coater (108 auto, Cressington Scientific Instruments Ltd., Watford, UK). Finally, the coated samples were observed and imaged using a field emission scanning electron microscope (FE-SEM; MIRA 3 XMH, Tescan, Brno, Czech Republic) equipped with an SE detector at 15 keV.
RESULTS AND DISCUSSION
The major diagnostic characteristics of Boehmeria are as follows: habit, stem color, phyllotaxis, leaf shape, leaf margin, leaf apex, presence of white trichomes on the abaxial surface, leaf texture, inflorescence type, number of stamens in male flowers, presence of pedicels, stigma shape, presence of stipes on the fruit, achene shape, presence of wings or appendages on the achene, and trichomes on the achene (Gaudichaud, 1830; Blume, 1857; Weddell, 1869; Satake, 1936; Liu and Huang, 1976; Wang, 1981a, 1981b; Chen et al., 2003; Lee, 2003; Tateishi, 2006; Liang, 2009; Wilmot-Dear and Friis, 2013; Cho, 2018; Kim, 2018). The recent studies have also confirmed that most of the diagnostic characteristics proposed in previous research are important for distinguishing Korean taxa of Boehmeria (Jo et al., 2021, 2023, 2024; Jo, 2023). In the present study, the micromorphological characteristics of the stem, abaxial leaf surface, and perianth of staminate flower were found to be highly important for species identification. These diagnostic characteristics are presented (Figs. 1–3).
Trichome of stem
Stem trichomes in Boehmeria were classified into four types: Type A, found in B. nivea, B. platanifolia, and B. tricuspis, consists of assurgent-hirsute trichomes that are coarser and more rigid than hispid trichomes but more flexible (Fig. 1A–C); Type B, occurring in B. japonica, B. holosericea, and B. quelpaertensis, has assurgent-hirsutulous trichomes that are rougher, stiffer, and shorter than those of Type A (Fig. 1D–F); Type C, observed in B. nipononivea, has strigose trichomes that are appressed and lie flat on the stem surface (Fig. 1G). In the remaining taxa, Type D has strigillose trichomes that are appressed and shorter than the strigose type—dense in B. hirtella and B. nakashimae (Fig. 1H, I), whereas Type E is sparse or nearly glabrous in B. sieboldiana, B. nakaiana, B. taquetii, B. spicata, B. gracilis, B. paraspicata, and B. silvestrii (Fig. 1J–P).
Trichome of abaxial leaf surface
Trichome type of midvein on leaf abaxial surface
The trichomes on the midvein of the abaxial leaf surface were classified into four types—hirsute, strigose, strigillose, and sericeous—depending on the taxa (Fig. 2). Hirsute trichomes were observed in B. nivea, B. japonica, B. platanifolia, B. tricuspis, and B. quelpaertensis (Fig. 2A, C–E, G); strigose trichomes were found only in B. nipononivea (Fig. 2B); strigillose trichomes were observed in B. sieboldiana, B. nakaiana, B. taquetii, B. hirtella, B. nakashimae, B. spicata, B. gracilis, B. paraspicata, and B. silvestrii (Fig. 2H–P); and sericeous trichomes were identified as a distinctive feature of B. holosericea (Fig. 2F). The basal cells of trichomes are generally well developed in long, erect hairs but tend to be reduced or absent in apressed trichomes, probably to support the longer trichomes mechanically. Among the Korean taxa of Boehmeria, species with numerous or erect trichomes on the abaxial leaf surface (e.g., B. nivea, B. japonica, B. platanifolia, B. tricuspis, B. quelpaertensis, B. holosericea, B. hirtella, and B. nakashimae) tend to inhabit coastal or open sunny areas, whereas those distributed along mountain valleys or moist habitats generally have fewer or more appressed trichomes. These findings suggest that the distribution and types of trichomes are diverse and likely related to environmental adaptation.
Trichome type of veinlet on leaf abaxial surface
This characteristic was classified into five types according to the taxa (Fig. 2). Lanate trichomes were observed only in B. nivea and B. nipononivea (Fig. 2A, B); uncinate bristles, characterized by hooked apices, were found in B. spicata, B. gracilis, B. paraspicata, and B. silvestrii (Fig. 2M–P); hirsutulous trichomes were present in B. nipononivea, B. japonica, B. platanifolia, B. tricuspis, B. quelpaertensis, B. hirtella, and B. nakashimae (Fig. 2B–E, G, K, L); sericeous trichomes were unique to B. holosericea (Fig. 2F); and glabrous surfaces were observed in B. sieboldiana, B. nakaiana, and B. taquetii (Fig. 2H–J). Uncinate bristles were generally distributed across the abaxial leaf surface in all taxa, but the types of trichomes covering them varied among species. This characteristic is therefore considered a primitive one. Trichomes are taxonomically significant (Gangadhara and Inamdar, 1977) and have been reported to serve as useful phenotypic indicators for understanding evolutionary trends and phylogenetic relationships among species in certain taxa (Cantino, 1990; Khosroshahi and Salmaki, 2019; Watts and Kariyat, 2021).
Perianth appendage of staminate flower
The appendage at the apex of the staminate flower perianth has been recognized as a useful diagnostic characteristic for distinguishing taxa (Wilmot-Dear and Friis, 2013). In the present study, the appendage was found to be indistinct or poorly developed in B. nivea, B. nipononivea, B. sieboldiana, B. nakaiana, and B. taquetii, (Fig. 3A, H–K), whereas it was clearly developed only in the B. japonica complex and B. spicata complex (Fig. 3B–G, M–P). Although the function of the appendage remains unknown, it encloses the anther and is presumed to function in anther protection and pollen dispersal.
Trichome of staminate flower
The trichomes on the perianth of male flowers were classified into four types (Fig. 3). Type A, with hirsute trichomes, was observed in B. nivea, B. platanifolia, and B. tricuspis (Fig. 3A–C); Type B, with hirsutulous trichomes, was found in B. japonica, B. quelpaertensis, and B. hirtella (Fig. 3D–F); Type C, characterized by sericeous trichomes, was observed exclusively in B. holosericea (Fig. 3G); and Type D, with strigillose trichomes, occurred in the remaining taxa (Fig. 3H–P). This characteristic showed diverse patterns of trichome distribution—hirsute, hirsutulous, sericeous, and strigillose—depending on the taxa, and was confirmed to be useful for distinguishing among species.
TAXONOMIC TREATMENT
Boehmeria Jacq., Enum. Syst. Pl. 9: 31, 1760.—TYPE: B. ramiflora Jacq.
Duretia Gaudich., Voy. Uranie 500, 1826 [1830], nom. nud. Splitgerbera Miq., Comm. Phytogr. 3: 133, pl. 14, 1840.—TYPE: S. japonica Miq.
Ramium Kuntze, Revis. Gen. Pl. 2: 631, 1891, nom. superfl. based on Boehmeria Jacq.
Korean name: Mo-si-pul-sok (모시풀속: Lee, 1996b).
Herbs perennial, subshrub, shrub, or small tree, monoecious or dioecious, rhizomatous. Stems erect to descending or sometimes scrambling, simple to branched, shallowly or deeply sulcate, without stinging trichome. Leaves opposite, alternate, or rarely whorled, simple; stipules intrapetiolar or interpetiolar, free or connate at 1/5–1/2 of the base, caducous, reflexed or not reflexed; petioles equal or unequal in opposite leaves; blades 3-veined, margin serrate-dentate, bidentate, or crenate, apex unlobed or rarely 2-, 3-, or 5-lobed, densely punctiform lithocyst with cystoliths on the adaxial surface. Inflorescences axillary, spicate or raceme of spicates with glomerules. Flowers unisexual; bracts small, scarious; bracteoles small, scarious; staminate flowers often 4-merous or rarely 2–7-merous; pedicels very short stipitate or sessile; perianth lobes cleft, appendaged or without appendages; filaments linear, inflexed, anthers basifixed; ovary rudimentary, clavate or sub-globose; pistillate flowers usually sessile; perianth tubes tubular, necks 2–4-toothed; stamens absent; ovary unicarpellous, orthotropous, enclosed by perianth, styles persistent, elongate, plumose, stigma linear or hooked. Infructescences glomerules loose or dense at fruiting. Achenes enclosed in the persistent perianth, winged or without wings, membranous, not lustrous.
Species: about 47–150 (13 species in Korea).
Distribution: East to West Africa, Indian Ocean Islands, East to West Asia, Oceania, Pacific Islands, and North to South America (mostly tropical, subtropical, and rarely temperate regions).
Key to the species of Boehmeria in Korea
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1. Stem piths rather hollow; leaves alternate; stipules intrapetiolar, often connate at the base; abaxial surfaces of leaf often densely white lanate; achenes without wings. (Sect. Tilocnide 모시풀절)
2. Stems densely assurgent-hirsute; middle leaf blades often broadly ovate, adaxial surface of leaf midveins convex; staminate perianths hirsute; achenes hirsute ··················································································· 1. B. nivea 모시풀
2. Stems densely strigose; middle leaf blades often elliptic-ovate, adaxial surface midveins flat; staminate perianths strigillose; achenes strigillose ·························································································· 2. B. nipononivea 섬모시풀
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1. Stem piths not hollow; leaves opposite except on distal stem; stipules interpetiolar, free; abaxial surfaces of leaf not white lanate; achenes winged. (Sect. Duretia 왜모시풀절)
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3. Herbs perennial; pistillate inflorescences often branched; staminate inflorescences often branched; achenes not scabrous.
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4. Staminate perianths appendaged; achenes hirsute, hirsutulous, or sericeous. (Ser. Longispicae 왜모시풀열)
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5. Stems shallowly sulcate; infructescences glomerules average less than 6 mm.
6. Stems densely assurgent-hirsutulous; leaf apexes often unlobed, densely assurgent-hirsutulous on the adaxial surface; staminate flowers perianths hirsutulous; infructescences dense; achenes hirsutulous ····· 3. B. japonica 왜모시풀
6. Stems often densely assurgent-hirsute; leaf apexes 3- or 5-lobed, densely assurgent-hirsute on the adaxial surface; staminate flowers perianths hirsute; infructescences loose; achenes hirsute ·········· 6. B. platanifolia 개모시풀
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5. Stems deeply sulcate; infructescences glomerules above average 6 mm.
7. Habitats coastal; middle leaf stipules triangular-ovate, blades often broadly ovate, margins crenulate to serrulatecrenulate, uniform, abaxial surfaces densely velvety sericeous on the veinlets; staminate perianths sericeous; achenes sericeous ··························································································· 4. B. holosericea 왕모시풀
7. Habitats forest; middle leaf stipules narrowly triangular, blades often broadly depressed ovate, margins serrate-dentate, gradually larger distally, abaxial surfaces densely hirsutulous on the veinlets; staminate perianths hirsutulous; achenes hirsutulous ························································· 5. B. quelpaertensis 제주모시풀
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4. Staminate perianths without appendages; achenes strigillose. (Ser. Sieboldianae 긴잎모시풀열)
8. Stems sparsely strigillose or sub-glabrous; middle leaf blades rhombic-ovate, elliptic-ovate, or rhombic-lanceolate to lanceolate-ovate; abaxial surfaces sparsely strigillose or sub-glabrous on the veinlets ···· 7. B. sieboldiana 긴잎모시풀
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8. Stems densely strigillose; middle leaf blades ovate or broadly ovate; abaxial surfaces densely hirsutulous on the veinlets
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3. Subshrubs or shrubs; pistillate inflorescences unbranched; staminate inflorescences often unbranched; achenes scabrous. (Ser. Spicatae 좀깨잎나무열)
10. Shrubs with woody stem throughout; woody stems often densely black pubescent; stems many-branched; middle leaf blades rhombic to rhombic-ovate ········································································ 10. B. spicata 좀깨잎나무
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10. Subshrubs with woody stem only at base; woody stems glabrous; stems a few branched; middle leaf blades not rhombic to rhombic-ovate.
11. Leaf apexes 3- or 5-lobed ·········································································· 13. B. silvestrii 참거북꼬리
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11. Leaf apexes unlobed.
12. Middle leaf blades ovate to broadly ovate, margins serrate-dentate, teeth gradually larger distally, apexes caudate or narrowly acute ··········································································· 11. B. paraspicata 풀거북꼬리
12. Middle leaf blades elliptic, broadly elliptic, ovate, or broadly depressed ovate, margins serrulate-dentate, teeth subequal distally, apexes short caudate or cuspidate ······································ 12. B. gracilis 톱거북꼬리
I. Section Tilocnide Blume, Mus. Bot. 2: 210, 1856. Boehmeria subgen. Tilocnide (Blume) Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 474, 1936.
Korean name: Mo-si-pul-jeol (모시풀절: new common name).
Stems piths rather hollow. Leaves alternate, stipules intrapetiolar, often connate at the base, abaxial surfaces often densely white lanate. Achenes without wings.
1. Boehmeria nivea (L.) Gaudich., Voy. Uranie 499, 1830; Urtica nivea L., Sp. Pl. 985, 1753; B. nivea (L.) Hook. f. & Arn., Bot. Beechey Voy. 5: 214, 1841 [1837], nom. illeg., later homonym.; Ramium niveum (L.) Kuntze, Revis. Gen. Pl. 2: 632, 1891, nom. superfl. based on B. nivea (L.) Hook. f. & Arn.—TYPE: CHINA. Unknown collector s.n. (lectotype: LINN, photo!, designated by Ghafoor, 1977) (Fig. 4).
U. candicans Burm. f., Fl. Indica 197, 1768; B. candicans (Burm. f.) Hassk., Pl. Jav. Rar. 203, 1848; B. nivea (L.) Hook. f. & Arn. non Gaudich. var. candicans (Burm. f.) Wedd., Prodr. [A. P. de Candolle] 16: 207, 1869.—TYPE: INDONESIA. Ambon, Rumphius, Hortus Amboinensis 5: t. 79, 1747 (lectotype: photo!, designated by Wilmot-Dear and Friis, 2013).
U. tenacissima Roxb., Suppl. Observ. Sunn Hemp Bengal 41, 1811; B. tenacissima (Roxb.) Blume, Mus. Bot. 2: 211, 1857; B. nivea var. tenacissima (Roxb.) Miq., Fl. Ned. Ind. 1: 253, 1859.—TYPE: [icon] Roxburgh drawing 1670 (lectotype: K, photo!, designated by Turner, 2013); W. Roxburgh s.n. (epitype: BR, photo!, designated by Turner, 2013).
B. compacta Blume, Mus. Bot. 2: 210, 1857; R. compactum (Blume) Kuntze, Revis. Gen. Pl. 2: 633, 1891, nom. superfl. based on B. compacta Blume—TYPE: INDONESIA. Java, Unknown collector s.n. (holotype: L, photo!).
B. utilis André, Revue Horticole (Paris) 62: 184, 1890.—TYPE: [icon] S. Hugard (holotype: photo!).
B. nivea f. grosseserrata Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 476, 1936.—TYPE: JAPAN. Honshu, Prov. Bittyu, 5 Sep 1902, J. Nikai 1066 (holotype: ?, not seen).
B. thailandica Yahara, Acta Phytotax. Geobot. 32: 4, 1981.—TYPE: THAILAND. Phitsanulok, Thung Salang Luang, Tagawa et al. 11233 (syntype: KYO, photo!); S.P. et al. 121 (syntype: KYO, not seen); Tagawa et al. 2059 (syntype: KYO, not seen).
Korean name: Mo-si-pul (모시풀: Mori, 1922).
Shrubs monoecious. Stems erect to descending, 0.5–1.8 m tall, 2.2–14 mm in diam., shallowly sulcate, yellow green, densely assurgent-hirsute, not strigose; woody stems brown or yellowish brown, glabrescent, barks smooth. Leaves pairs subequal in size; stipules free or connate at 1/5–1/3 of the base, not reflexed, caducous, narrowly triangular, 8.1–15.5 × 1.5–7.9 mm, yellow green, glabrous on the adaxial surface, densely assurgent-hirsute on the abaxial surface and vein; petioles 4.1–14.8 cm long, 1–2.8 mm in diam., yellow green with light red or yellow green, densely assurgent-hirsute; middle leaf blades broadly ovate, broadly depressed ovate, orbicular-ovate, orbicular, or deltate-ovate, 10–22.8 × 7.9–21.4 cm, base cordate, broadly cuneate, or truncate, margin serrulate-dentate, uniform, teeth 19–32 on one side, apex unlobed, caudate or acute, adaxial surface green or yellow green, densely assurgent-hirsute mixed with hirsutulous, densely punctiform lithocysts with cystoliths, midvein convex, abaxial surface often light gray to white or white mixed with yellow green, densely assurgent-hirsute along midvein, densely white lanate along veinlets, texture chartaceous or thin membranous. Inflorescences axillary, spicate with glomerules; staminate inflorescences much branched on middle part of stem, 2–5.6 cm long; pistillate inflorescences much branched on upper half part of stem, 2.2–8.7 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 3- or 6-merous, 4.6–8.1 mm wide; pedicels 0.1–0.8 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 0.9–2.7 × 1.1–1.6 mm, without appendages, yellow green, hirsute; filaments linear, inflexed, 2–3.5 mm long, yellow green, anthers basifixed, 1–1.9 × 0.8–1.8 mm, white; ovary rudimentary, clavate; pistillate flowers 0.9–2.1 mm long, sessile; perianth tubes rhomboid to obovoid, 0.5–1.3 × 0.3–0.8 mm, yellow green, hirsute; necks 2-lobed; styles 1, linear, plumose, 0.3–1 mm long, white, stigma linear. Infructescences glomerules loose at fruiting, 2.6–3.9 mm wide. Achenes 46–75 per a glomerule, obovoid, 1–1.6 × 0.6–1 mm, base cuneate, hirsute.
Phenology: Flowering September to October, fruiting late October to late November.
Chromosome number: 2n = 28, 42, 56 (Rabéchault, 1951; Okabe, 1963; Liu and Chen, 2000; Yang et al., 2000).
Distribution: India, Nepal, Bhutan, Bangladesh, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia, Philippines, Taiwan, China, Japan, and Korea [Gyeonggi-do, Chungcheongnam-do, Jeollabuk-do (including cultivation), Jeollanam-do (including cultivation), Gyeongsangbuk-do (cultivation), Gyeongsangnam-do, Incheon-si, Jeju-do, and Ulleungdo Island] (Jo, 2023).
Habitat: Populations presumed to be wild plants grow naturally near the coast of southwest, sunny places, and cultivated for fiber, mosi songpyeon (모시 송편), mosi tea (모시 차), or mosi latte (모시 라떼).
Representative specimens examined: KOREA. Chung-cheongnam-do: Seocheon-gun, Hansan-myeon, Chungjeol-ro, 1089, 11 Nov 2021, H.J. Jo et al. HJ211111-001–004 (ANH); Taean-gun, Meondong Beach, 9 Sep 2020, H.J. Jo et al. HJ200909-001 (ANH). Gyeongsangbuk-do: Gyeongsan-si, Wachon-myeon, Sowol-ri, 232-8, 10 Sep 2019, H.J. Jo et al. HJ190910-001 (ANH); Ulleung-gun, Dodong-ri, 16 Oct 2016, H.J. Jo et al. HJ161016-001 (ANH); Ulleung-eup, Dodong-ri, 272, 31 Aug 2018, H.J. Jo et al. HJ180831-001–005 (ANH). Gyeongsangnam-do: Geoje-si, Jangmok-myeon, Sibang-ri, 24 Aug 2020, H.J. Jo et al. HJ200824-001 (ANH); Sadeung-myeon, Sagok-ri, 874-9, 2 Oct 2022, H.J. Jo et al. HJ221002-002 (ANH); Sacheon-si, Waryong-dong, 395-1, 9 Oct 2018, H.J. Jo et al. HJ181009-004, 005 (ANH). Jeollabuk-do: Buan-gun, Naesosa Temple, 23 Oct 2019, H.J. Jo et al. HJ190523-001, 002 (ANH). Jeollanam-do: Goheung-gun, Dongil-myeon, Deokheung-ri, 661-2, 14 Oct 2021, H.J. Jo et al. HJ211014-001–004 (ANH). Jeju-do: Jeju-si, Jocheon-eup, Gyorae-ri, 856, 24 Apr 2019, H.J. Jo et al. HJ190424-002 (ANH).
Taxonomic note: Boehmeria nivea can be easily distinguished from related taxa by its alternate leaves and white trichomes on the abaxial surface of leaves (Figs. 2, 4). However, it is often confused with the morphologically similar B. nipononivea. Chen et al. (2003) differentiated between B. nivea and B. nipononivea based on morphological characteristics, such as the stem trichomes, connation of stipules, and color and trichomes on the abaxial surface of leaves. However, even within a single individual, the stipules may be partially or completely divided depending on the stage of leaf development in the axil. The overall appearance is generally white when the lanate trichomes on the abaxial surface of leaves are dense, and green when sparse (i.e., there is continuous variation). In this study, the connation of stipules and color of the abaxial surface of leaves were not identified as key characteristics. However, the stem trichome was a distinct differentiating characteristic (Figs. 1, 4, 5). Tateishi (2006) distinguished the two taxa based on the trichomes on stems and petioles as well as leaf shapes. In the present study, B. nivea was characterized by densely hirsute stems and petioles, usually broadly ovate middle leaves, a convex midvein on the adaxial surface of leaves, and hirsute trichomes on the perianths of staminate flowers and achenes (Figs. 1–5). On the other hand, B. nipononivea was characterized by densely strigose stems and petioles, usually elliptic-ovate middle leaves, a flat midvein on the adaxial surface of leaves, and strigillose trichomes on the perianths of staminate flowers and achenes (Figs. 1–5). Thus, the results of this study support the opinion of Tateishi (2006).
Boehmeria nivea is primarily cultivated in Asia countries, including India, Thailand, the Philippines, China, and Korea (Liu et al., 2010). There is considerable intraspecific variation, which is consistent with its broad distribution range and diverse habitats. It has been cultivated in China for at least 3,000 to 4,700 years (Chen et al., 2003; Wang et al., 2021). In Korea, it is commonly recognized as a naturalized species from China (Kim, 2018). In this study, old populations were found in Ulleungdo Island and various regions in southern Korea, suggesting that these are native habitats. However, further studies are needed to determine whether it is indeed a native plant.
2. Boehmeria nipononivea Koidz., Acta Phytotax. Geobot. 10: 223, 1941; B. nivea subsp. nipononivea (Koidz.) Kitam., Acta Phytotax. Geobot. 20: 208, 1962; B. nivea var. nipononivea (Koidz.) W. T. Wang, Acta Bot. Yunnan. 3: 320, 1981; B. nivea var. concolor f. nipononivea (Koidz.) Kitam. ex H. Ohba, Fl. Jap. (Iwatsuki et al., eds.) 2a: 102, 2006.—TYPE: not located (Fig. 5).
B. nivea var. reticulata Blume, Mus. Bot. 2: 211, 1857.—TYPE: JAPAN. P.F. von Siebold s.n. (lectotype: L, photo!, designated by Monro et al., 2025).
B. nivea (L.) Hook. et Arn. non Gaudich. var. concolor Makino, Bot. Mag. (Tokyo) 23: 251, 1909; B. frutescens (Thunb.) Thunb. var. concolor (Makino) Nakai, Bot. Mag. (Tokyo) 41: 514, 1927; B. nipononivea var. concolor (Makino) Ohwi, Fl. Jap. 441, 1953; B. nivea subsp. nipononivea f. concolor (Makino) Kitam., Col. Ill. Herb. Pl. Jap. 2: 339, 1961; B. nivea subsp. nipononivea f. concolor (Makino) Kitam., Acta Phytotax. Geobot. 20: 208, 1962; B. nivea var. concolor f. concolor (Makino) Kitam. ex H. Ohba, Fl. Jap. (Iwatsuki et al., eds.) 2a: 102, 2006.—TYPE: JAPAN. Honshu, Prov. Yamashiro, Takao, 7 Nov 1893, T. Makino s.n. (syntype: MAK?, TI?, not seen); Prov. Harima, Mt. Masui, 1902, K. Ikeda s.n. (syntype: MAK?, TI?, not seen).
B. nivea var. viridula Yamam., J. Soc. Trop. Agric. 4: 50, 1932; B. frutescens var. viridula (Yamam.) T. Suzuki, Short Fl. Formos. 47, 1936.—TYPE: TAIWAN. Prov. Kwarenko, Beisan, 21 Aug 1929, Y. Yamamoto 542 (syntype: ?, not seen); Prov. Kwarenko, between Doba and Taiheizan, 28 Jul 1928, S. Suzuki 1168 (syntype: ?, not seen).
Korean name: Seom-mo-si-pul (섬모시풀: Lee, 1969).
Shrubs monoecious. Stems erect to descending, 0.7–2.5 m tall, 2.2–17 mm in diam., shallowly sulcate, yellow green, densely strigose, not hirsute; woody stems brown or yellowish brown, glabrescent, barks smooth. Leaves pairs subequal in size; stipules free or 1/5–1/2 connate at the base, not reflexed, caducous, narrowly triangular, 10.5–15.6 × 2.2–6.2 mm, yellow green, glabrous on the adaxial surface, densely strigose on the abaxial surface and vein; petioles 2–12.1 cm long, 0.7–1.8 mm in diam., green or red, densely strigose; middle leaf blades ovate, elliptic-ovate, lanceolate-ovate, or broadly ovate, 8–19.8 × 4.7–12.1 cm, base cuneate, broadly cuneate, sub-cordate, rounded, or truncate, margin serrulate-dentate, uniform, teeth 12–29 on one side, apex unlobed, caudate to short caudate, adaxial surface green or yellow green, densely assurgent-hirsute mixed with hirsutulous, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface often gray, gray white, gray green, or yellow green, densely strigose along midvein, densely white lanate or densely hirsutulous along veinlets, texture chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences much branched on middle part of stem, 2.2–7.7 cm long; pistillate inflorescences much branched on upper half part of stem, 2.2–5.5 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, 4.8–6.7 mm wide; pedicels 0.2–1.5 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 0.8–1.7 × 1.1–1.4 mm, without appendages, yellow green, strigillose; filaments linear, inflexed, 1.8–2.8 mm long, yellow green, anthers basifixed, 0.8–1.2 × 0.9–1.2 mm, white; ovary rudimentary, clavate; pistillate flowers 1–1.6 mm long, rhomboid to obovoid, 0.7–1.2 × 0.3–0.6 mm, yellow green, strigillose; necks 2-lobed; styles 1, linear, plumose, 0.3–0.7 mm long, white, stigma linear. Infructescences glomerules loose at fruiting, 2.7–3.5 mm wide. Achenes 42–91 per a glomerule, obovoid, 0.9–1.4 mm long, 0.6–0.8 mm wide, base cuneate, strigillose.
Phenology: Flowering September to October, fruiting late October to November.
Chromosome number: 2n = 28 (Okabe, 1963; Zhang et al., 1996).
Distribution: Thailand, Cambodia, Vietnam, Malaysia, Indonesia, Philippines, Taiwan, China, Japan, and Korea [Chungcheongnam-do, Jeollabuk-do, Jeollanam-do (including cultivation), Gyeongsangbuk-do (cultivation), Gyeongsangnamdo, and Jeju-do except Ulleungdo Island] (Jo, 2023).
Habitat: Near the coast of Southwest and Jejudo Island, sunny places, and cultivated for fiber, mosi songpyeon (모시 송편), or mosi tea (모시 차).
Representative specimens examined: KOREA. Gyeong-sangbuk-do: Andong-si, Namseon-myeon, Mt. Gallasan, 21 Jun 2022, H.J. Jo et al. HJ220621-001 (ANH). Jeju-do: Seogwipo-si, Bomok-dong, 260–7, 24 Aug 2022, H.J. Jo et al. HJ220824-006 (ANH); Hahyo-dong, 863, 16 Oct 2018, H.J. Jo et al. HJ181016-008, 009 (ANH); Jungmunsaekdal Beach, 15 Sep 2020, H.J. Jo et al. HJ200915-002 (ANH); Jeju-si, Gujwa-eup, Deonggae Coast, 27 Aug 2021, H.J. Jo et al. HJ210827-004 (ANH); Hado-ri, 970–3, 27 Aug 2021, H.J. Jo et al. HJ210827-005 (ANH); Jongdal-ri, Yongnuni Ooreum, 4 Sep 2018, H.J. Jo et al. HJ180904-005–007 (ANH); Hallim-eup, Hyeopjae-ri, Biyangdo Island, 8 Apr 2022, H.J. Jo et al. HJ220408-002, 009 (ANH); Jocheon-eup, Bengdui Pool, 3 Sep 2018, H.J. Jo et al. HJ180903-012–015 (ANH); Gyorae-ri, 856, 24 Apr 2019, H.J. Jo et al. HJ190424-001 (ANH); Yeon-dong, 2442, 24 Aug 2022, H.J. Jo et al. HJ220824-005 (ANH). Jeollanam-do: Mokpo-si, Mt. Yudalsan, 22 Jun 2020, H.J. Jo et al. HJ200622-001 (ANH); Yeosu-si, Geomundo Island, 11 Oct 2016, H.J. Jo et al. HJ161011-001 (ANH).
Taxonomic note: This taxon is widely distributed across Southeast and Northeast Asia. It has been assigned to different ranks owing to variation among populations in neighboring countries. In China, Chen et al. (2003) treated this taxon as B. nivea var. tenacissima and considered it a wild species of B. nivea. In the present study, var. tenacissima was re-examined based on the protologue and the lectotype designated by Turner (2013), and was found to share morphological characters with B. nivea var. nivea, such as densely hirsute plants, broadly ovate leaves, and hirsute achenes; therefore, it is treated here as a synonym of B. nivea. In Japan, Tateishi (2006) considered this taxon as var. concolor and distinguished between f. nippononivea and f. concolor based on whether the abaxial surface of the leaves is white or light green, respectively. The color of the abaxial surface of the leaves exhibits continuous variation, even within a single individual, ranging from light green to pale white or white, depending on the lanate density (Figs. 2, 5).
Based on a review of protologues and typifications, as well as morphological studies, the taxon is clearly distinguished from B. nivea by its densely strigose stems, usually ellipticovate leaves, flat midvein on the adaxial surface of leaves, and strigillose perianth of staminate flowers and achenes (Figs. 1–5). Therefore, this taxon is recognized at the species level, and B. nipononivea, which has priority at the species level, is treated as the correct name.
II. Section Duretia Blume, Mus. Bot. 2: 212, 1856.
Boehmeria subgen. Duretia (Blume) Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 478, 1936.
Korean name: Wae-mo-si-pul-jeol (왜모시풀절: new common name).
Stems piths solid. Leaves opposite except on distal stem, stipules interpetiolar, free, abaxial surfaces not white lanate. Achenes winged.
A. Series Longispicae (Satake) W. T. Wang, Acta Bot. Yunnan. 3: 401, 1981.
Boehmeria subgen. Duretia sect. Longispicae Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 521, 1936.—TYPE: B. japonica (L. f.) Miq. (designated here).
Korean name: Wae-mo-si-pul-yeol (왜모시풀열: new common name).
Herbs perennial. Stems yellow green or red in node, densely assurgent-hirsute or hirsutulous. Leaves stipules reflexed, densely strigillose on the adaxial surface. Staminate perianths appendaged. Pistillate inflorescences often branched. Achenes hirsute, hirsutulous, or sericeous.
3. Boehmeria japonica (L. f.) Miq., Ann. Mus. Bot. Lugd.-Bat. 3: 131, 1867; U. japonica L. f., Suppl. PI. 418, 1781; U. elongata J. F. Gmel., Syst. Nat., ed. 13[bis] 2: 269, 1791, nom. superfl. based on U. japonica L. f.; B. platyphylla D. Don var. japonica (L. f.) Wedd., Fam. Urtic. 365, 1856.—TYPE: JAPAN. C.P. Thunberg s.n. (lectotype: LINN, photo!, designated by Yahara, 1984) (Fig. 6).
B. longispica Steud., Flora 33: 260, 1850; B. japonica var. longispica (Steud.) Yahara., J. Jap. Bot. 59: 320, 1984.—TYPE: CHINA. Ningpo, Aug 1844, Fortune 85A (lectotype: P, photo!, designated by Yahara, 1984); China. 1845, Fortune 85A (isolectotype: K, photo!)
U. macrophylla Thunb., Syst. Veg., ed. 14: 850, 1784; B. macrophylla (Thunb.) Siebold & Zucc. non Hornem., Abh. Math.-Phys. Cl. Königl. Bayer. Akad. Wiss. 4: 215, 1846, nom. illeg., later homonym; B. platyphylla var. macrophylla (Thunb.) Wedd., Prodr. 16: 213, 1869, nom. superfl. based on B. platyphylla var. japonica (L. f.) Wedd.; B. grandifolia (Thunb.) Wedd., Ann. Sci. Nat., Bot., ser. 4, 1: 199, 1854, nom. superfl. based on U. macrophylla Thunb.; B. miqueliana Tanaka, Bull. Sc. Hort. Inst. Kyushu Imp. Univ. 1: 198, 1925, nom. superfl. based on U. macrophylla Thunb.—TYPE: JAPAN. C.P. Thunberg 22160 (holotype: UPS, photo!).
B. longispica var. appendiculata Blume, Mus. Bot. 2: 221, 1857; B. japonica var. appendiculata (Blume) Yahara., J. Jap. Bot. 59: 134, 1984.—TYPE: JAPAN. Unknown collector s.n. (lectotype: L, photo!, designated by Yahara, 1984).
B. longispica var. heterodonta Blume, Mus. Bot. 2: 221, 1857.—TYPE: JAPAN. Unknown collector s.n. (lectotype: L, photo!, designated by Wilmot-Dear and Friis, 2013).
B. spicata (Thunb.) Thunb. var. duploserrata C. H. Wright, J. Linn. Soc., Bot. 26: 488, 1899.—TYPE: CHINA. Chekiang?, H.J. Hicken s.n. (holotype: K, photo!).
B. pachystachya Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 524, 1936.—TYPE: JAPAN. Honshu, Prov. Awa, Mt. Kiyozumi, 5 Nov 1935, Y. Satake & Y. Jotani 3557 (holotype: TI, photo!).
B. pilushanensis Y. C. Liu & F. Y. Lu, Quart. J. Chin. Forest. 11: 102, 1978; B. taiwaniana var. pilushanensis (Liu & Lu) S. S. Ying, Col. Ill. Fl. Taiwan 3: 466, 1988.—TYPE: Lu & Ou 3552 (holotype: TCF, photo!).
Korean name: Wae-mo-si-pul (왜모시풀: Chung et al., 1949).
Herbs perennial, monoecious or dioecious. Stems lignified at fruiting, erect to descending, shallowly sulcate, 0.6–1.8 m tall, 1.7–4.3 mm in diam., yellow green or red in node, densely assurgent-hirsutulous. Leaves pairs subequal in size; stipules caducous, lanceolate, 9.1–13.6 mm long, 2.4–3.7 mm wide, yellow green, densely strigillose on the adaxial surface, densely strigillose on the abaxial surface, densely assurgent-hirsutulous or strigillose on the vein; petioles 3–11.3 cm long, 1–2.1 mm in diam., red or yellow green, densely assurgent-hirsutulous or strigillose; middle leaf blades ovate, broadly ovate, broadly depressed ovate, or orbicular-ovate, 10.1–35.8 × 7.5–30.5 cm, base broadly cuneate, sub-cordate, truncate, or sub-rounded, margin serrate-dentate or serrate-bidentate, gradually larger distally, teeth 9–18 on one side, apex often unlobed or rarely 3- or 5-lobed, acuminate, caudate, or acute, adaxial surface green or yellow green, densely assurgent-hirsutulous, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface yellow green, densely assurgent-hirsute along midvein, densely hirsutulous along veinlets, texture chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences branched on middle part of stem, 17.5–30.3 cm long; pistillate inflorescences often branched or unbranched on upper half part of stem, 9–35.5 cm long, glomerules dense at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 3- or 7-merous, 3.3–6.1 mm wide; pedicels 0.2–3 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 1.2–1.8 × 0.8–1.1 mm, yellow green, hirsutulous; filaments linear, inflexed, 1.7–3 mm long, yellow green, anthers basifixed, 0.8–1.1 × 0.8–1 mm, white; ovary rudimentary, clavate; pistillate flowers 3.2–4.6 mm long, sessile; perianth tubes rhomboid to obovoid, 0.9–2.2 × 0.5–1.4 mm, yellow green, hirsutulous; necks 2-lobed; styles 1, linear, plumose, 2.1–3.4 mm long, white, stigma linear. Infructescences glomerules dense at fruiting, 3.7–5 mm wide. Achenes 66–104 per a glomerule, rhomboid to obovoid, 1.7–2.2 × 1.2–1.7 mm, base cuneate, hirsutulous.
Phenology: Flowering July to September, fruiting September to November.
Distribution: China, Taiwan, Japan, and Korea (All provinces except Ulleungdo Island) (Jo, 2023).
Habitat: Forest margins, mountain streams, and shady places.
Representative specimens examined: KOREA. Chungcheongbuk-do: Cheongju-si, Mt. Seondusan, 4 Jun 2021, H.J. Jo et al. HJ210604-004 (ANH). Chungcheongnam-do: Cheongyang-gun, Mt. Chilgapsan, Naengcheon Valley, 9 Jun 2016, H.J. Jo et al. HJ160609-005 (ANH); Gunsan-si, Wolmyeong Park, 22 Oct 2020, H.J. Jo et al. HJ201022-004 (ANH). Daegu-si: Dalseong-gun, Mt. Choejeongsan, Daewonsa Temple, 4 Oct 2019, H.J. Jo et al. HJ191004-004 (ANH). Gyeongsangbuk-do: Bonghwa-gun, Mt. Munmyeongsan, 18 Sep 2018, H.J. Jo et al. HJ180918-001 (ANH). Gyeonggi-do: Gimpo-si, Mt. Seungmasan, 27 Aug 2020, H.J. Jo et al. HJ200827-001 (ANH). Gyeongsangnam-do: Changnyeong-gun, Docheon-myeon, Docheon-ri, 1206, 22 Apr 2022, H.J. Jo et al. HJ220422-001 (ANH). Gangwon-do: Pyeongchang-gun, Mitan-myeon, Mt. Baegunsan, 2 Jul 2021, H.J. Jo et al. HJ210702-003 (ANH). Jeollabuk-do: Gunsan-si, Wolmyeong Lake, 22 Oct 2021, H.J. Jo et al. HJ211022-001 (ANH). Jeju-do: Jeju-si, Aewol-eup, Jokeunnokkome Oreum, 28 Aug 2021, H.J. Jo et al. HJ210828-007 (ANH). Jeollanam-do: Damyang-gun, Mt. Yonggusan, 5 Aug 2022, H.J. Jo et al. HJ220805-002 (ANH). Ulsan-si: Ulju-gun, Sangbuk-myeon, Mt. Baegunsan, 11 Sep 2016, H.J. Jo et al. HJ160911-003 (ANH).
Taxonomic note: This taxon is native to Eastern Asia. Many names have been published primarily based on variation in leaf margins. However, these characteristics show continuous variation within individuals or populations. In this study, all of the names are treated as synonyms. Boehmeria japonica (L. f.) Miq. (1867) should be treated as the correct name due to priority at the species level, rather than B. longispica Steud. (1850) (Turland et al. 2018).
Boehmeria japonica is easily distinguished from B. holosericea by its shallowly sulcate stems, serrate-dentate or serrate-bidentate margins, absence of dense white sericeous trichomes on the abaxial surface of leaves, infructescences with glomerules with an average width of less than 5 mm, and hirsutulous trichomes on the perianth of staminate flowers and achenes (Figs. 2, 3, 6, 7) (Jo et al., 2024). Additionally, B. japonica can be easily distinguished from B. quelpaertensis by its shallowly sulcate stems, sparser hirsutulous stems, lanceolate stipules, densely assurgent-hirsutulous abaxial leaf surfaces, infructescences with glomerules with an average width of less than 5 mm, and rhomboid to obovoid and cuneate achenes (Figs. 6, 8). This species is also distinguished from B. platanifolia by its densely hirsutulous stems, abaxial surface of leaves, perianth of staminate flowers and achenes, often not 3-lobed at the apex of leaves, and dense infructescences (Figs. 1–3, 9) (Jo et al., 2024).
4. Boehmeria holosericea Blume, Mus. Bot. 2: 221, 1857; B. platyphylla var. holosericea Wedd., Prodr. 16: 212, 1869.—TYPE: JAPAN. H. Bürger s.n. (lectotype: L, photo!, designated by Wilmot-Dear and Friis, 2013) (Fig. 7).
B. hispidula Blume, Mus. Bot. 2: 223, 1857; Ramium hispidulum Kuntze, Revis. Gen. Pl. 2: 633, 1891.—TYPE: JAPAN. H. Bürger s.n. (lectotype: L, photo!, designated by Wilmot-Dear and Friis, 2013).
B. pannosa Nakai & Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 510, 1936; B. pannosa Nakai & Satake in Oka, Tennenkinenbutu-Tyosa-Hokoku, Syokubutu 16: 4, 1936. —TYPE: JAPAN. Kyushu, Prov. Tsushima, 2 Aug 1921, ♂, T. Nakai s.n. (syntype: TI, photo!); Kyushu, Prov. Osumi, Birozima Ialand, Aug 1933, ♀, G. Oka s.n. (syntype: TI, not seen).
Korean name: Wang-mo-si-pul (왕모시풀: Chung et al., 1949).
Herbs perennial, monoecious, or dioecious. Stems lignified at fruiting, erect to descending, deeply sulcate, 0.7–1 m tall, 4.3–7.7 mm in diam., yellow green in upper part, brown in lower and middle part, densely assurgent-hirsutulous. Leaves pairs subequal in size; stipules caducous, triangular-ovate, 9.0–19.8 × 3.7–6.2 mm, yellow green, densely sericeous on the adaxial surface, densely velvety sericeous on the abaxial surface and vein; petioles 1.7–6.3 cm long, 2.3–3.6 mm in diam., yellow green, densely velvety sericeous; lower leaf disarticulated except upper half part of stem leaf at flowering; middle leaf blades broadly ovate to orbicular-ovate, 15.1–18.9 × 13.0–16 cm, base cordate, rounded, or truncate, margin crenulate to serrulate-crenulate, uniform, teeth 26–40 on one side, apex unlobed, acute, adaxial surface green, densely sericeous, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface yellow green, densely velvety sericeous along midvein and veinlets, texture thick chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences often branched or unbranched on middle part of stem, 7.5–22.5 cm long; pistillate inflorescences often unbranched or rarely branched on upper half part of stem, 11.2–18.1 cm long, glomerules dense at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 3-merous, 3.4–4.9 mm wide; pedicels 0.3–1.8 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 1.1–1.5 × 0.8–1 mm, yellow green, sericeous; filaments linear, inflexed, 1.7–2.7 mm long, yellow green, anthers basifixed, 0.8–1 mm long, 0.6–1 mm wide, white; ovary rudimentary, clavate; pistillate flowers 2.6–3.7 mm long, sessile; perianth tubes narrowly rhomboid, 1.3–2 × 0.4–0.9 mm, yellow green, sericeous; necks 2-lobed; styles 1, linear, plumose, 1.2–2.2 mm long, white, stigma linear. Infructescences glomerules dense glomerules at fruiting, 6.6–8.8 mm wide. Achenes 261–396 per a glomerule, narrowly obovoid to obovoid, 1.8–3.5 × 0.7–1.8 mm, base narrowly cuneate or attenuate, sericeous.
Phenology: Flowering July to September, fruiting September to November.
Chromosome number: 2n = 28, 42 (Yahara, 1983b).
Distribution: Japan and Korea (Jeollabuk-do, Jeollanam-do, Gyeongsangnam-do, and Jeju-do) (Jo, 2023).
Habitat: Rocky areas or roadsides near the coast of southwest Island and Jejudo Island, and sunny places.
Representative specimens examined: KOREA. Busan-si: Nam-gu, Yongho-dong, Igidae Park, 24 Aug 2020, H.J. Jo et al. HJ200824-002–004 (ANH). Gyeongsangnam-do: Geoje-si, Nambu-myeon, Galgot-ri, 14, 2 Oct 2022, H.J. Jo et al. HJ221002-004 (ANH). Jeju-do: Jeju-si, Dodui-dong, 1657–5, 25 Aug 2022, H.J. Jo et al. HJ220825-001 (ANH); Gujwa-eup, Dongbok-ri, 716–2, 29 Jul 2021, H.J. Jo et al. HJ210729-002, 003 (ANH); Gujwa-eup, Gujwahaeal-ro, 64, 17 Sep 2019, H.J. Jo et al. HJ190917-003, 004 (ANH); Hallim-eup, Hyeopjae-ri, Biyangdo Island, 26 Jul 2022, H.J. Jo et al. HJ220726-001 (ANH); Jocheon-eup, Sinheung-ri, 14, 19 Oct 2021, H.J. Jo et al. HJ211019-002 (ANH). Jeollanam-do: Yeosu-si, Chodo Island, 12 Aug 2022, H.J. Jo et al. HJ220812-001, 002 (ANH).
Taxonomic note: This taxon has traditionally been recognized as B. pannosa and treated as distinct from B. holosericea (Satake, 1936; Ohwi, 1965; Lee, 1996a, 1996b; Tateishi, 2006; Kim, 2018). However, a review of the protologues and type specimens revealed that the two taxa share various characteristics, such as stem trichomes, leaf shapes, trichomes on both leaf surfaces, and inflorescence shapes (Figs. 1, 2, 7). Therefore, B. pannosa was treated as a synonym of B. holosericea based on priority.
Chen et al. (2003) considered B. holosericea a synonym of B. japonica; however, in this study, the two taxa differed in morphological characteristics, such as sulcate stems, the density of stem trichomes, stipule shapes, leaf margin shapes, leaf trichomes, and trichomes on the perianth of staminate flowers and achenes (Figs. 1, 2, 6, 8). Therefore, the two taxa are treated as distinct independent species.
Boehmeria holosericea is easily distinguished from related taxa by its habitat on coastal rocks, falling leaves below the middle of stems, and brown middle stems. However, among related taxa, B. splitgerbera Koidz. resembles B. holosericea in habitat and morphology. This taxon was first mentioned in Korea as B. biloba Wedd., nom. superfl. (Tteok-mo-si-pul) by Lee (2003). Wilmot-Dear and Friis (2013) reported that B. splitgerbera is distributed in Japan and Korea. However, according to the results of this study, B. splitgerbera is found only along the coast of Japan and is cultivated only in the Wando Arboretum of Korea. Boehmeria holosericea is characterized by broadly ovate to orbicular-ovate middle leaves, crenulate to serrulate-crenulate margins, an unlobed apex, and densely sericeous trichomes on the adaxial surface (Fig. 7). Boehmeria splitgerbera is characterized by obovate-orbicular to ovate-orbicular middle leaves, serrulate margins, a 2- to 3-lobed apex, and densely scabrous trichomes on the adaxial surface. These distinct morphological characteristics support their classification as separate species.
5. Boehmeria quelpaertensis Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 514, 1936.—TYPE: KOREA. Quelpaert Island, 3 Nov 1917, T. Nakai 4999 (holotype: TI, photo!) (Fig. 8).
B. quelpaertensis f. glabra Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 516, 1936.—TYPE: KOREA. Quelpaert Island, 3 Nov 1917, T. Nakai s.n.? (holotype: TI, photo!).
B. dura Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 529, 1936.—TYPE: JAPAN. Honshu, Prov. Izu, prope Simoda, 5 Sep 1935, Y. Satake 3587 (holotype: TI, photo!).
B. hatusimae Satake, J. Jap. Bot. 14: 203, 1938.—TYPE: JAPAN. Kyushu, Prov. Tikuzen, 8 Nov 1936, S. Hatusima s.n. (holotype: TI, photo!).
B. grandissima var. serrulata Satake, J. Jap. Bot. 14: 511, 1938.—TYPE: JAPAN. Kyushu, Prov. Tikuzen, Sikanosima Island, 1937, S. Hatusima 25 (holotype: TI, not seen).
Korean name: Je-ju-mo-si-pul (제주모시풀: Lee, 1969).
Herbs perennial, monoecious or dioecious. Stems lignified at fruiting, erect to descending, deeply sulcate, 0.9–1.9 m tall, 3–5.7 mm in diam., yellow green or red in node, densely assurgent-hirsutulous. Leaves pairs subequal in size; stipules caducous, narrowly triangular, 9.2–16.2 × 4.2–7 mm, yellow green, densely strigillose on the adaxial surface, sparsely strigillose on the abaxial surface and vein; petioles 4.5–20.1 cm long, 1.6–3.4 mm in diam., yellow green with red or red, densely strigillose; middle leaf blades broadly depressed ovate, broadly ovate, orbicular-ovate, sub-orbicular, or broadly deltate-ovate, 16.5–28.3 × 16.6–30.5 cm, base cordate, sub-cordate, truncate, or broadly cuneate, margin serrate-dentate, gradually larger distally, teeth 14–26 on one side, apex unlobed, acute or narrowly acute, adaxial surface green or yellow green, densely strigillose, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface yellow green, densely assurgent-hirsute along midvein, densely hirsutulous along veinlets, texture thick chartaceous, chartaceous, or thin membranous. Inflorescences axillary, spicate with glomerules; staminate inflorescences branched on middle part of stem, 13.6–16 cm long; pistillate inflorescences often branched or unbranched on upper half part of stem, 8–46.8 cm long, glomerules dense at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 3-merous, 4.3–6 mm wide; pedicels 0.3–1.8 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 1.1–1.5 × 1–1.2 mm, yellow green, hirsutulous; filaments linear, inflexed, 1.9–2.5 mm long, yellow green, anthers basifixed, 0.8–1 × 0.9–1.2 mm, white; ovary rudimentary, clavate; pistillate flowers 2.8–3.8 mm long, sessile; perianth tubes rhomboid to obovoid, 1.3–1.7 × 0.5–1 mm, yellow green, hirsutulous; necks 2-lobed; styles 1, linear, plumose, 1.4–2.2 mm long, white, stigma linear. Infructescences glomerules dense at fruiting, 6–8 mm wide. Achenes 83–265 per a glomerule, narrowly obovoid to obovoid, 2.4–3.2 × 1.4–2.1 mm, base narrowly cuneate or attenuate, hirsutulous.
Phenology: Flowering July to September, fruiting September to November.
Chromosome number: 2n = 42 (Yahara, 1983b).
Distribution: Japan and Korea (Jeollabuk-do, Jeollanam-do, Gyeongsangnam-do, and Jeju-do) (Jo, 2023).
Habitat: Forest margins or roadsides near the coast of Southwest and Jejudo Island, and shady places.
Representative specimens examined: KOREA. Busan-si: Nam-gu, Yongho-dong, Igidae Park, 24 Aug 2020, H.J. Jo et al. HJ200824-006–010 (ANH). Gyeongsangnam-do: Geoje-si, Jangmok-myeon, Heungnam Beach, 24 Aug 2020, H.J. Jo et al. HJ200824-011, 013, 014 (ANH). Jeju-do: Jeju-si, Hallim-eup, Hyeopjae-ri, Biyangdo Island, 26 Jul 2022, H.J. Jo et al. HJ220726-010, 011 (ANH); Seogwipo-si, Seondeoksa Temple, 16 Oct 2018, H.J. Jo et al. HJ181016-006 (ANH). Jeollanam-do: Yeosu-si, Nam-myeon, Yusong-ri, San, 125-1, 3 Sep 2021, J.H. Kim HJ210903-002 (ANH).
Taxonomic note: The identities of B. quelpaertensis along with B. nakaiana, B. taquetii, and B. hirtella, which are distributed on Jeju-do Island as Korean endemic species, are unresolved (Kim, 2018). Based on fieldwork and observations of additional specimens, the identity of B. quelpaertensis was confirmed; however, the species is also distributed in Japan. Wilmot-Dear and Friis (2013) treated B. quelpaertensis as a synonym of B. holosericea. Furthermore, the two taxa are distributed along the southwestern coast and Jeju-do Island of Korea; owing to their morphological similarities, they are commonly identified as the same taxon. However, B. quelpaertensis is found in coastal mountainous areas and is characterized by narrowly triangular stipules, rounded pentagonal petioles in transverse sections, petioles ranging from 4.5 to 20.1 cm in length, usually broadly depressed ovate middle leaves with serrate-dentate margins, gradually larger teeth towards the distal end, usually branched pistillate inflorescences, and hirsutulous trichomes on the abaxial surface of leaves, perianth of staminate flowers, and achenes (Figs. 2, 3, 8) (Jo et al., 2024). Boehmeria holosericea is found in coastal rocky areas and is characterized by triangular-ovate stipules, compressed pentagonal petioles in transverse sections, petioles ranging from 1.7 to 6.3 cm in length, broadly ovate to orbicular-ovate middle leaves with crenulate margins, uniform teeth, usually unbranched pistillate inflorescences, and sericeous trichomes on the abaxial surface of leaves, perianth of staminate flowers, and achenes (Figs. 2, 3, 7) (Jo et al., 2024).
6. Boehmeria platanifolia (Maxim.) C. H. Wright, J. Linn. Soc., Bot. 26: 486, 1899; B. japonica var. platanifoliam Franch. & Sav. ex Maxim., Mélanges Biol. Bull. Phys.-Math. Acad. Imp. Sci. Saint-Pétersbourg 9: 643, 1876; B. longispica var. platanifolia (Franch. & Sav. ex Maxim.) Franch. & Sav., Enum. Pl. Jap. 2: 497, 1878; B. miqueliana var. platanifolia (Franch. & Sav. ex Maxim.) Hatsusima, Bull. Exp. For. Kyushu Imp. Univ. 5: 55, 1934; B. maximowiczii Nakai & Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 522, 1936, nom. superfl. based on B. japonica var. platanifoliam Franch. & Sav. ex Maxim.—TYPE: JAPAN. Jugo Hakone, Aug ?, P.A.L. Savatier 1117 (holotype: P, photo!); jugo Hakone, Aug ?, P. A. L. Savatier 1117 (isotype: P, photo!) (Fig. 9).
B. platyphylla var. tricuspis Hance, J. Bot. 12: 261, 1874; B. japonica var. tricuspidem Maxim., Mélanges Biol. Bull. Phys.-Math. Acad. Imp. Sci. Saint-Pétersbourg 9: 643, 1876; B. longispica var. tricuspis Franch. & Sav., Enum. Pl. Jap. 2: 497, 1878; B. platanifolia var. tricuspis Matsum., Index Pl. Jap. 2: 42, 1912; B. tricuspis (Hance) Makino, Bot. Mag. (Tokyo) 26: 387, 1912.—TYPE: CHINA. Zhejiang, Kiukiang, 3 Oct 1873, Otto van Moellendorff s.n. (holotype: BM, photo!).
B. tricuspis f. viridipes Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 481, 1936.—TYPE: JAPAN. Honshu, Prov. Awa, Mt. Kiyozumi, 5 Nov 1935, Y. Satake s.n. (holotype: ?, not seen).
B. taiwaniana Nakai & Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 526, 1936.—TYPE: TAIWAN. Nanto. Saramao, 11 Aug 1919, E. Matsuda 14 (holotype: TI, photo!).
B. robusta Nakai & Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 528, 1936.—TYPE: JAPAN. Honshu, Prov. Sagami, 4 Oct 1931, K. Hisauchi s.n. (holotype: TI, photo!).
Korean name: Gae-mo-si-pul (개모시풀: Chung et al., 1949).
Herbs perennial, monoecious or dioecious. Stems lignified at fruiting, erect to descending, shallowly sulcate, 0.7–1.8 m tall, 2–6 mm in diam., yellow green or red in node, densely assurgent-hirsute or hirsutulous. Leaves rarely whorled, pairs subequal in size; stipules caducous, narrowly triangular, 9.1–18.2 × 2.2–4.8 mm, yellow green, densely strigillose on the adaxial surface, densely strigillose on the abaxial surface, densely assurgent-hirsutulous or strigillose on the vein; petioles 6.2–29.7 cm long, 1.1–2.4 mm in diam., red or green, densely assurgent-hirsute or strigillose; middle leaf blades oblate to 5-angled broadly ovate, depressed orbicular-ovate, transversely oblong, broadly ovate, or broadly depressed ovate, 12.3–31.4 × 14.4–30.2 cm, base broadly truncate, sub-cordate, sub-rounded, or broadly cuneate, margin serrate-bidentate, incised in apex, gradually larger distally, teeth 5–17 on one side, apex 3- or 5-lobed, acuminate, acute, or caudate, adaxial surface green or yellow green, densely assurgent-hirsute, densely punctiform lithocysts with cystoliths, midvein convex, abaxial surface yellow green, densely assurgent-hirsute along midvein, densely hirsutulous along veinlets, texture chartaceous or thin membranous. Inflorescences axillary, spicate with glomerules; staminate inflorescences branched on middle part of stem, 21.2–35.6 cm long; pistillate inflorescences often branched or unbranched on upper half part of stem, 12–41.2 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 2-, 3- or 5-merous, 3.4–5.8 mm wide; pedicels 0.1–1.4 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 0.8–1.7 × 0.7–1.6 mm, yellow green, hirsute; filaments linear, inflexed, 1.6–2.9 mm long, yellow green, anthers basifixed, 0.8–1.2 × 0.7–1.2 mm, white; ovary rudimentary, clavate; pistillate flowers 2.2–4.4 mm long, sessile; perianth tubes rhomboid to obovoid, 0.7–1.5 × 0.3–0.8 mm, yellow green, hirsute; necks 2-lobed; styles 1, linear, plumose, 1.2–3.3 mm long, white, stigma linear. Infructescences glomerules loose at fruiting, 3.3–5.3 mm wide. Achenes 46–181 per a glomerule, rhomboid to obovoid or sub-orbicular, 1.1–2.4 × 0.8–1.8 mm, base cuneate or rounded, hirsute.
Phenology: Flowering July to September, fruiting September to November.
Distribution: Taiwan, China, Japan, and Korea (all provinces) (Jo, 2023).
Habitat: Forest margins, mountain streams, and shady places.
Representative specimens examined: Chungcheongbuk-do: Cheongju-si, Mt. Seondusan, 4 Jun 2021, H.J. Jo et al. HJ210604-003 (ANH). Chungcheongnam-do: Cheonan-si, Mt. Gwangdeoksan, Gwangdeoksa Temple, 12 Sep 2016 (ANH). Daegu-si: Dalseong-gun, Mt. Choejeongsan, Daewonsa Temple, 4 Oct 2019, H.J. Jo et al. HJ191004-005 (ANH). Gyeongsangbuk-do: Andong-si, Songcheon-dong, 26 May 2022, H.J. Jo et al. HJ220526-004 (ANH). Gyeonggi-do: Yangpyeong-gun, Mt. Yongmunsan, Sanasa Valley, 20 May 2022, H.J. Jo et al. HJ220520-001 (ANH). Gyeongsangnam-do: Goseong-gun, Mt. Yeonhwasan, 16 Jul 2019, H.J. Jo et al. HJ190716-003 (ANH). Gangwon-do: Pyeongchang-gun, Mitan-myeon, Mt. Baegunsan, 2 Jul 2021, H.J. Jo et al. HJ210702-004 (ANH). Jeollabuk-do: Sunchang-gun, Geumgok Reservoir, 6 Aug 2019, H.J. Jo et al. HJ190806-002 (ANH). Jeju-do: Jeju-si, Aewol-eup, Jokeunnokkome Oreum, 28 Aug 2021, H.J. Jo et al. HJ210828-001 (ANH). Jeollanam-do: Mokpo-si, Mt. Yudalsan, 22 Jun 2020, H.J. Jo et al. HJ200622-002 (ANH).
Taxonomic note: There is confusion in the literature on this taxon owing to conflicting authorities, such as B. platanifolia (Maxim.) Franch. & Sav. ex F. B. Forbes & Hemsl., B. platanifolia (Franch. & Sav.) C. H. Wright, B. platanifolia Franch. & Sav., B. platanifolia Franch. & Sav. ex C. H. Wright, B. platanifolia (Franch. & Sav. ex Maxim.) C. H. Wright, and B. platanifolia (Maxim.) C. H. Wright (Ohwi, 1953, 1965; Kitamura and Murata, 1961; Makino, 1961, 1989; Lee, 1996a, 1996b; Lee, 2003; Lee, 2006; Tateishi, 2006; Wilmot-Dear and Friis, 2013; Kim, 2018; Korea National Arboretum, 2020; Missouri Botanical Garden, 2025; WFO, 2025). Franchet and Savatier (1875) first reported this taxon as B. platanifolia Franch. & Sav.; however, this name is considered an invalid name because of the lack of a description. Subsequently, Maximowicz (1876) validly published the infraspecific taxon B. japonica var. platanifolia, and according to Art. 35.1 of the Shenzhen Code, ‘platanifolia’ is attributed to Maxim (Turland et al., 2018). Later, Wright (1899) treated Maxim’s name as the basionym and recombined it at the species level. According to Art. 46.6 of the Shenzhen Code, the name was validly published by C. H. Wright, rather than F. B. Forbes & Hemsl. (Turland et al., 2018).
In this study, based on a review of taxonomic names and morphological characteristics, the taxon was recognized at the species level. The correct name for this taxon should be either B. platanifolia (Franch. & Sav. ex Maxim.) C. H. Wright or B. platanifolia (Maxim.) C. H. Wright. It resembles B. japonica morphologically but is distinctly characterized by densely assurgent-hirsute trichomes on the stems, adaxial surface of leaves, perianth of staminate flowers, and achenes (Figs. 1–3, 6, 9). Additionally, its leaves have a distinct 3- to 5-lobed apex, and its infructescences are sparse.
B. Series Sieboldianae (Satake) H. J. Jo & G. Y. Chung, stat. nov.
Boehmeria subgen. Duretia sect. Sieboldianae Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 486, 1936.—TYPE: B. sieboldiana Blume (designated here).
Korean name: Gin-ip-mo-si-pul-yeol (긴잎모시풀열: new common name).
Herbs perennial. Stems yellow green or red in node, sparsely or densely strigillose or sub-glabrous. Leaves stipules reflexed or not reflexed, sparsely or densely strigillose on the adaxial surface. Staminate perianths without appendages. Pistillate inflorescences often branched. Achenes strigillose.
7. Boehmeria sieboldiana Blume, Mus. Bot. 2: 220, 1857; B. platyphylla var. sieboldiana (Blume) Wedd., Prodr. 16: 213, 1869; B. longispica var. sieboldiana (Blume) Franch. & Sav., Enum. Pl. Jap. 1: 440, 1875.—TYPE: JAPAN. H. Bürger s.n. (lectotype: L, photo!, designated here); P.F. von Siebold s.n. (syntypes: L, not seen) (Fig. 10).
B. formosana Hayata, J. Coll. Sci. Imp. Univ. Tokyo 30: 281, 1911.—TYPE: TAIWAN. Taito, May 1906, T. Kawakami & Z. Kobayashi 1472b (syntype: TI, photo!); Shiringai, Jun 1905, G. Nakahara 68 (syntype: ?, not seen).
B. taquetii Nakai, Repert. Spec. Nov. Regni Veg. 13: 267, 1914.—TYPE: KOREA. Quelpaert Island, Aug 1911, E.J. Taquet 5965 (Lectotype: TI, photo!, designated here); isolectotype: E, photo!, designated here).
B. pseudosieboldiana Honda, Bot. Mag. (Tokyo) 45: 469, 1931.—TYPE: JAPAN. Kiusiu, Prov. Higo, Omura, 12 Aug 1929, K. Mayebara 298 (holotype: TI, not seen).
B. nakaiana Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 491, 1936.—TYPE: KOREA. Quelpaert Island, 31 Oct 1917, T. Nakai 6156 (holotype: TI, photo!).
B. stenostachya Satake, J. Jap. Bot. 14: 202, 1938; B. sieboldiana var. stenostachya (Satake) Kitam., Col. Ill. Herb. Pl. Jap. 2: 340, 1961.—TYPE: JAPAN. Kyushu, Prov. Hizen, Mt. Kurokamiyama, 6 Sep 1930, S. Hatusima s.n. (holotype: TI, photo!).
Korean name: Gin-ip-mo-si-pul (긴잎모시풀: Chung et al., 1937).
Herbs perennial, monoecious or dioecious. Stems lignified at fruiting, erect to descending, shallowly sulcate, 0.5–1.6 m tall, 1.7–4 mm in diam., yellow green or red in node and sulcate, sparsely strigillose or sub-glabrous; piths not hollow. Leaves pairs subequal in size; stipules not reflexed, caducous, narrowly triangular, 7.2–10 × 1.2–2.2 mm, yellow green or pale red, sparsely strigillose on the adaxial surface, sparsely strigillose on the abaxial surface and vein; petioles 2.7–12.4 cm long, 0.7–1.5 mm in diam., red or red with yellow green, sparsely strigillose; middle leaf blades rhombic-ovate, ellipticovate, or rhombic-lanceolate to lanceolate-ovate, 8–25.6 × 3.8–12.8 cm, base cuneate, obtuse, or rounded, margin serrulate-dentate, uniform, teeth 8–26 on one side, apex unlobed, caudate, adaxial surface green, sparsely strigillose, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface yellow green, sparsely strigillose or sub-glabrous along midvein and veinlets, texture often chartaceous or thin membranous. Inflorescences axillary, spicate with glomerules; staminate inflorescences often branched or unbranched on middle part of stem, 8.5–19.5 cm long; pistillate inflorescences often branched or unbranched on upper half part of stem, 6.7–23.8 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 2- or 3-merous, 4.2–6 mm wide; pedicels 0.1–0.3 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 0.6–1.5 × 0.7–1.2 mm, green, strigillose; filaments linear, inflexed, 1.7–2.7 mm long, yellow green, anthers basifixed, 0.6–1.1 mm long, 0.6–1 mm wide, white; ovary rudimentary, clavate; pistillate flowers 1.9–3.3 mm long, sessile; perianth tubes rhomboid to obovoid, 0.6–1.2 × 0.3–0.8 mm, often yellow green or red, strigillose; necks 2-lobed; styles 1, linear, plumose, 1.3–2.4 mm long, white, stigma linear. Infructescences glomerules loose at fruiting, 2.7–4 mm wide. Achenes 13–41 per a glomerule, rhomboid-obovoid to sub-orbicular, winged, 1.3–2.1 × 0.9–1.8 mm, base cuneate or obtuse.
Phenology: Flowering July to September, fruiting September to November.
Chromosome number: 2n = 56 (Yahara, 1983b).
Distribution: Taiwan, China, Japan, and Korea (Jeollanam-do and Jeju-do) (Jo, 2023).
Habitat: Forest margins or roadsides near the coast of Southwest and Jejudo Island, and shady places.
Representative specimens examined: KOREA. Jeju-do: Jeju-si, Aewol-eup, Noro Oreum, 26 Jul 2022, H.J. Jo et al. HJ220726-005–008 (ANH); Jocheon-eup, Banong Oreum, 3 Sep 2018, H.J. Jo et al. HJ180903-002–007 (ANH); Hallim-eup, Mundoji Oreum, 19 Sep 2019, H.J. Jo et al. HJ190919-001 (ANH); Jocheon-eup, Mul Oreum, 23 Jul 2020, H.J. Jo et al. HJ200723-001 (ANH). Seogwipo-si, Seongpanak Parasitic Cone, 17 Oct 2018, H.J. Jo et al. HJ181017-001 (ANH); Sillongnam-ro, 1115, 22 Jul 2020, H.J. Jo et al. HJ200722-001 (ANH). Jeollanam-do: Yeosu-si, Nam-myeon, Yusong-ri, San, 154-3, 3 Sep 2021, J.H. Kim HJ210903-001 (ANH).
Taxonomic note: Boehmeria sieboldiana has been divided into several species or variants owing to the diversity of leaf shapes. Korean endemic species B. nakaiana and B. taquetii, which are distributed on Jejudo Island, have often been confused with B. sieboldiana owing to their shared morphological characteristics (Nakai, 1914; Satake, 1936; Kim, 2018). Boehmeria. nakaiana has almost no grooves on its stem, unlike B. sieboldiana, and its leaves are smaller and narrower (Satake, 1936). Boehmeria taquetii has serrate leaves and smaller flowers (Nakai, 1914). In this study, these characteristics showed continuous variation within individuals or populations, and the two taxa were treated as synonyms of B. sieboldiana.
Boehmeria sieboldiana is easily distinguished from B. hirtella by morphological characteristics, such as sparsely strigillose or sub-glabrous stems, middle leaves with rhombic-ovate, elliptic-ovate, or rhombic-lanceolate to lanceolate-ovate shapes, strigillose trichomes on the perianth of staminate flowers, and loose glomerules of infructescences (Figs. 1, 3, 10). Boehmeria hirtella is characterized by densely strigillose stems and perianth of staminate flowers, middle leaves with ovate or broadly ovate shapes, densely hirsutulous trichomes on the abaxial surface of leaves, and denser glomerules of infructescences (Figs. 1, 3, 11).
8. Boehmeria hirtella Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 493, 1936.—TYPE: KOREA. Quelpaert Island, 16 Aug 1910, E. Taquet 4433 (holotype: TI, photo!) (Fig. 11).
B. sieboldiana var. ovata Satake, J. Jap. Bot. 14: 263, 1938.—TYPE: JAPAN. Honshu, Prov. Uzen, Mt. Iide-san, Aug 1937, T. Suzuki s.n. (holotype: TI, photo!).
B. sieboldiana var. sikokiana Satake, J. Jap. Bot. 14: 263, 1938.—TYPE: JAPAN. Sikoku, Prov. Iyo, Mt. Isizuti, 6 Jul 1915, G. Koidzumi s.n. (holotype: TI, photo!).
Korean name: Teol-gin-ip-mo-si-pul (털긴잎모시풀: Lee, 1969).
Herbs perennial, monoecious or dioecious. Stems lignified at fruiting, erect to descending, shallowly sulcate, 0.8–1.6 m tall, 2.4–5.1 mm in diam., yellow green, densely strigillose; piths not hollow. Leaves pairs subequal in size; stipules caducous, narrowly triangular, 7.3–15.6 × 2.1–3.7 mm, yellow green, sparsely strigillose on the adaxial surface, sparsely strigillose on the abaxial surface, densely strigillose on the vein; petioles 2.8–14.1 cm long, 1.2–2.3 mm in diam., red or green, sparsely or densely strigillose; middle leaf blades ovate or broadly ovate, 12.6–22.2 × 7.9–15.4 cm, base broadly cuneate or cuneate, margin serrate or serrulate-dentate, uniform to gradually larger distally, teeth 13–20 on one side, apex unlobed, caudate or acuminate, adaxial surface green, densely strigillose, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface yellow green, sparsely strigillose along midvein, densely hirsutulous along veinlets, texture often chartaceous or thin membranous. Inflorescences axillary, spicate with glomerules; staminate inflorescences branched on middle part of stem, 13.6–17.5 cm long; pistillate inflorescences often branched or unbranched on upper half part of stem, 7.9–23.5 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 3-or 5-merous, 3.1–4.8 mm wide; pedicels 0.2–0.7 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 0.7–1.3 × 0.8–1 mm, yellow green, hirsutulous; filaments linear, inflexed, 1.6–2.1 mm long, yellow green, anthers basifixed, 0.7–1.2 × 0.6–1.3 mm, white; ovary rudimentary, clavate; pistillate flowers 2.9–4.4 mm long, sessile; perianth tubes rhomboid to obovoid, 0.9–1.5 × 0.5–0.9 mm, yellow green, strigillose; necks 2-lobed; styles 1, linear, plumose, 1.9–3 mm long, white, stigma linear. Infructescences glomerules loose at fruiting, 3.9–6 mm wide. Achenes 23–72 per a glomerule, rhomboid-obovoid to sub-orbicular, winged, 1.8–2.7 × 1.1–1.6 mm, base cuneate or obtuse.
Phenology: Flowering July to September, fruiting September to November.
Chromosome number: 2n = 42 (Yahara, 1983a).
Distribution: Japan and Korea (Jeollanam-do and Jeju-do) (Jo, 2023).
Habitat: Forest margins or roadsides near the coast of Southwest and Jejudo Island, and shady places.
Representative specimens examined: KOREA. Jeju-do: Jeju-si, Aewol-eup, Jokeunnokkome Oreum, 28 Aug 2021, H.J. Jo et al. HJ210828-004 (ANH); AraIl-dong, 371-7, 28 Aug 2021, H.J. Jo et al. HJ210828-005 (ANH); Gyorae Natural Recreation Forest, 18 Sep 2019, H.J. Jo et al. HJ190918-002, 003 (ANH); Jeju 4.3 Peace Park, 26 Jul 2019, H.J. Jo et al. HJ190726-003 (ANH); Jocheon-eup, Mul Oreum, 29 Aug 2021, H.J. Jo et al. HJ210829-003 (ANH). Seogwipo-si, Donneko, 14 Aug 2019, H.J. Jo et al. HJ190814-002 (ANH); Hawon-dong, San, 76-1, 16 Oct 2018, H.J. Jo et al. HJ181016-011 (ANH); Jungmun-dong, San, 1–3, 15 Sep 2020, H.J. Jo et al. HJ200915-008 (ANH); Sillongnam-ro, 1115, 20 Aug 2020, H.J. Jo et al. HJ200820-010 (ANH).
Taxonomic note: Boehmeria hirtella is a Korean endemic species distributed on Jejudo Island along with B. quelpaertensis, B. nakaiana, and B. taquetii; however, its identity has not been clear (Nakai, 1914; Satake, 1936; Kim, 2018). This taxon is often confused with B. sieboldiana owing to morphological similarities. However, it is clearly distinguished by its densely strigillose stems, ovate or broadly ovate middle leaves, densely hirsutulous trichomes on the veinlets and perianth of staminate flowers, and denser infructescences (Figs. 1–3, 10, 11).
9. Boehmeria nakashimae Yahara, J. Jap. Bot. 58: 88, 1983.—TYPE: JAPAN. Kyushu, Fukuoka Pref., Fukuoka City, Shikanoshima, 19 Sep 1937, K. Nakashima 15-a (holotype: TI, photo!), Nakashima 15-b (isotype: TI, photo!), Nakashima 15-c (isotype: TI, not seen) (Fig. 12).
Korean name: Je-ju-top-mo-si-pul (제주톱모시풀).
Herbs perennial, monoecious or dioecious. Stems lignified at fruiting, erect to descending, deeply sulcate, 1.2–2 m tall, 3.2–6.2 mm in diam., yellow green, densely strigillose; piths not hollow. Leaves pairs subequal in size; stipules caducous, lanceolate, 13.3–15.2 × 4.5–5.9 mm, yellow green, sparsely strigillose on the adaxial surface, sparsely strigillose on the abaxial surface, densely strigillose on the vein; petioles 6.1–14 cm long, 1.7–2.7 mm in diam., yellow green, densely strigillose; middle leaf blades ovate to broadly ovate, elliptic-ovate, or sub-orbicular, 19.6–27 × 11.3–25.5 cm, base rounded, broadly cuneate, or cordate, margin serrulate-dentate, uniform, teeth 17–29 on one side, apex unlobed, short caudate or narrowly acute, adaxial surface green or yellow green, densely strigillose, densely punctiform lithocysts with cystoliths, midvein flat, abaxial surface yellow green, densely strigillose along midvein, densely hirsutulous along veinlets, texture chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences branched on middle part of stem, 10.3–14.9 cm long; pistillate inflorescences often branched or unbranched on upper half part of stem, 10.7–19.8 cm long, glomerules dense at flowering. Flowers unisexual; staminate flowers 4-merous, 4.4–5.9 mm wide; pedicels 0.3–0.6 mm long, yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 1.1–1.4 × 0.8–1.1 mm, yellow green, strigillose; filaments linear, inflexed, 1.6–2.5 mm long, yellow green, anthers basifixed, 0.7–0.9 × 0.6–0.9 mm, white; ovary rudimentary, clavate; pistillate flowers 2.2–3.3 mm long, sessile; perianth tubes rhomboid to obovoid, 1–1.5 × 0.5–1.1 mm, yellow green, strigillose; necks 2-lobed; styles 1, linear, plumose, 1.2–1.9 mm long, white, stigma linear. Infructescences glomerules dense at fruiting, 3.8–5.4 mm wide. Achenes 32–119 per a glomerule, rhomboid to obovoid to sub-orbicular, winged, 1.9–2.3 × 1–1.4 mm, base cuneate or obtuse, strigillose.
Phenology: Flowering July to September, fruiting September to November.
Chromosome number: 2n = 42 (Okabe, 1963; Yahara, 1983b).
Distribution: Japan and Korea (Jeollanam-do and Jeju-do) (Jo, 2023; Jo et al., 2023).
Habitat: Forest margins or roadsides near the coast of Southwest and Jejudo Island, and shady places.
Representative specimens examined: KOREA. Jeju-do: Jeju-si, Aewol-eup, Bongseong-ri, Handae Oreum, 21 Oct 2021, H.J. Jo et al. HJ211021-002, 003 (ANH); Hallim-eup, Hyeopjae-ri, Biyangdo Island, 26 Jul 2022, H.J. Jo et al. HJ220726-002–004 (ANH); Hallim-eup, Mundoji Oreum, 19 Sep 2019, H.J. Jo et al. HJ190919-001 (ANH); Jocheon-eup, Banong Oreum, 29 Jul 2021, H.J. Jo et al. HJ210729-001 (ANH). Seogwipo-si, Hawon-dong, 799-1, 15 Sep 2020, H.J. Jo et al. HJ200915-003–005 (ANH); Sillongnam-ro, 1115, 20 Aug 2020, H.J. Jo et al. HJ200820-007 (ANH).
Taxonomic note: Boehmeria nakashimae is a Japanese endemic species (Yahara, 1983a); however, it was recently reported as an unrecorded species in Korea (Jo et al., 2023). It is similar in morphology to B. holosericea (Fig. 7). However, B. nakashimae is distinguished by various characteristics, including serrulate-dentate margins, strigillose trichomes on the stems, and abaxial surface of leaves, perianth of staminate flowers, and achenes (Figs. 1–3, 12). Furthermore, B. nakashimae is distinguished from B. hirtella by its shallowly sulcate stems and densely hirsutulous trichomes on the abaxial surface of leaves and perianth of staminate flowers (Figs. 1–3, 11, 12).
C. Series Spicatae (Satake) W. T. Wang, Bull. Bot. Res. 36: 810, 2016.
Boehmeria subgen. Duretia sect. Spicatae Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 480, 1936.—TYPE: B. spicata (Thunb.) Thunb. (designated by Wang, 2016).
Korean name: Jom-kkae-ip-na-mu-yeol (좀깨잎나무열: new common name).
Subshrubs or shrubs. Stems yellow green or red, sparsely strigillose or sub-glabrous, woody stem barks vertical-crack or vertical-plated. Leaves stipules not reflexed, glabrous on the adaxial surface. Staminate perianths appendaged. Pistillate inflorescences unbranched. Achenes scabrous.
10. Boehmeria spicata (Thunb.) Thunb., Trans. Linn. Soc. Lond. 2: 330, 1794; U. spicata Thunb., Syst. Veg., ed. 14: 850, 1784, pro part.—TYPE: JAPAN. 1984, C.P. Thunberg 22115 (lectotype: UPS, photo!, designated by Yahara, 1984) (Fig. 13).
B. spicata var. akari B lume, Mus. B ot. 2: 2 20, 1857.—TYPE: JAPAN. Unknown collector s.n. (holotype: L, not seen).
B. spicata var. tenera Blume, Mus. Bot. 2: 220, 1857; B. japonica var. tenera (Blume) Friis & Wilmot-Dear, Blumea 58: 193, 2013.—TYPE: JAPAN. Unknown collector s.n. (holotype: L, not seen).
B. spicata var. microphylla Nakai ex Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 483, 1936.—TYPE: JAPAN. Honshu, Prov. Izu, Mt. Amagi, 26 Jun 1931, T. Nakai s.n. (holotype: TI, photo!).
Korean name: Jom-kkae-ip-na-mu (좀깨잎나무: Chung et al., 1949).
Shrubs monoecious or dioecious. Stems erect to descending, 0.6–2.5 m tall, 1.2–29.0 mm in diam., shallowly sulcate, yellow green or red, sparsely strigillose or sub-glabrous; piths not hollow; woody stems brown or reddish brown, often densely black pubescent, barks vertical-plated. Leaves pairs subequal in size; stipules caducous, oblong-lanceolate, 3.9–7.0 × 1.1–1.9 mm, yellow green, sparsely strigillose on the abaxial surface and vein; petioles 2.2–7.5 cm long, 0.5–1.0 mm in diam., yellow green or red, sparsely strigillose; middle leaf blades rhombic to rhombic-ovate, 5.7–10.5 × 3.5–6.8 cm, base cuneate or broadly cuneate, margin serrate-dentate, gradually larger distally, teeth 4–9 on one side, apex unlobed, caudate or narrowly acute, adaxial surface green, sparsely strigillose, densely punctiform lithocysts with cystoliths, midvein convex, abaxial surface yellow green, sparsely strigillose along midvein, densely uncinate bristle along veinlets, texture chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences often unbranched or rarely branched on middle part of stem, 4.6–15.7 cm long; pistillate inflorescences 7.7–21.4 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, 3.6–4.5 mm wide; pedicels 0.3–1.3 mm long, often yellow green or red; perianth lobes cleft nearly to the middle, convex, elliptic, 0.7–1.0 × 0.7–1.1 mm, often yellow green or red, strigillose; filaments linear, inflexed, 1.2–1.9 mm long, yellow green, anthers basifixed, 0.8–1.0 × 0.6–1.0 mm, white; ovary rudimentary, clavate; pistillate flowers 3.4–5.1 mm long, sessile; perianth tubes rhomboid to obovoid, 1.1–2.1 × 0.6–1.3 mm, often yellow green or red, scabrous; necks 2-lobed; styles 1, linear, plumose, 2.2–3.7 mm long, often white or red, stigma linear. Infructescences glomerules loose at fruiting, 2.9–5.5 mm wide. Achenes 24–89 per a glomerule, rhomboid to obovoid, winged, 1.2–1.7 × 1.0–1.3 mm, base cuneate.
Phenology: Flowering June to September, fruiting September to November.
Distribution: China, Japan, and Korea (all provinces) (Jo, 2023).
Habitat: Forest margins, mountain streams, and shady or sunny places.
Representative specimens examined: KOREA. Busan-si: Haeundae-gu, U-dong, Mt. Jangsan, Yangwoon Falls, 20 Jul 2021, H.J. Jo et al. HJ210720-001 (ANH). Chungcheongbuk-do: Danyang-gun, Jungnyeongjae Hill, 5 Sep 2016, H.J. Jo et al. HJ160905-001 (ANH). Chungcheongnam-do: Cheonan-si, Mt. Gwangdeoksan, Gwangdeoksa Temple, 12 Sep 2016, H.J. Jo et al. HJ160912-002 (ANH). Daegu-si: Dalseong-gun, Mt. Choejeongsan, Daewonsa Temple, 4 Oct 2019, H.J. Jo et al. HJ191004-003 (ANH). Gyeongsangbuk-do: Andong-si, Mt. Gallasan, 9 Aug 2016, H.J. Jo et al. HJ160809-001 (ANH). Gyeongsangnam-do: Changwon-si, Jinhae-gu, Mt. Jangboksan, 8 Sep 2021, H.J. Jo et al. HJ210908-001 (ANH). Gangwon-do: Goseong-gun, Toseong-myeon, Hwaamsa Temple, 23 Sep 2016, H.J. Jo et al. HJ160923-001 (ANH). Jeollabuk-do: Jinan-gun, Mt. Unjangsan, 17 Jul 2016, H.J. Jo et al. HJ160717-001–005 (ANH). Jeju-do: Jeju-si, Aewol-eup, Musucheon Stream, 27 Jul 2016, H.J. Jo et al. HJ160727-001–003 (ANH); Seogwipo-si, Meochewat Forest Roadside, 27 Jul 2016, H.J. Jo et al. HJ160727-007 (ANH); Jeollanam-do: Damyang-gun, Mt. Yonggusan, 5 Aug 2022, H.J. Jo et al. HJ220805-001 (ANH).
Taxonomic note: Unlike related taxa, B. spicata is a shrub with many branching stems, vertical-plated bark, and rhombic to rhombic-ovate middle leaves (Fig. 13). Boehmeria paraspicata, which resembles B. spicata, has subshrubs, ovate to broadly ovate middle leaves, 9–19.1 cm long and 7.4–16.2 cm wide, whereas B. spicata is distinctly smaller (5.7–10.5 cm long and 3.5–6.8 cm wide) (Figs. 13, 14).
11. Boehmeria paraspicata Nakai, Veg. Mt. Apoi 19, 1930; B. tricuspis var. paraspicata (Nakai) Hara, Bot. Mag. (Tokyo) 48: 812, 1934; B. tricuspis subsp. paraspicata (Nakai) Kitam., Col. Ill. Herb. Pl. Jap. 2: 340, 1961.—TYPE: JAPAN. Hokkaido, Prov. Hidaka, Mt. Apoi, Aug 1928, T. Nakai s.n. (holotype: TI, photo!) (Fig. 14).
B. paraspicata Nakai ex Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 483, 1936, nom. illeg., later homonym.—TYPE: JAPAN. Hokkaido, Prov. Isikari, Kanayama, Aug 1916, G. Koidzumi s.n. (holotype: TI, photo!).
B. paraspicata f. viridis Satake, J. Fac. Sci. Univ. Tokyo, Sect. 3, Bot. 4: 485, 1936.—TYPE: JAPAN. Honshu, Prov. Sagami, Mt. Zinba, 19 Jul 1931, K. Hisauchi s.n. (holotype: TI, photo!).
Korean name: Pul-geo-buk-kko-ri (풀거북꼬리: Chung et al., 1949).
Subshrubs monoecious or dioecious. Stems erect to descending, 0.7–1.1 m tall, 1.8–4.1 mm in diam., branches shallowly sulcate, yellow green or red, sparsely strigillose or sub-glabrous; piths not hollow; woody stems brown, glabrous, barks vertical-crack. Leaves pairs subequal in size; stipules caducous, narrowly triangular, 8.2–14.7 mm long, 1.4–3.5 mm wide, yellow green, sparsely strigillose on the abaxial surface and vein; petioles 3.8–12.1 cm long, 0.8–1.7 mm in diam., green or red, sparsely strigillose; middle leaf blades ovate to broadly ovate, 9–19.1 × 7.4–16.2 cm, base broadly cuneate, margin serrate-dentate, gradually larger distally, teeth 6–14 on one side, apex unlobed, caudate or narrowly acute, adaxial surface green, sparsely strigillose, densely punctiform lithocysts with cystoliths, midvein convex, abaxial surface yellow green, sparsely strigillose along midvein, densely uncinate bristle along veinlets, texture often thin membranous or chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences often unbranched or rarely branched on middle part of stem, 5.9–28.5 cm long; pistillate inflorescences 9.4–23.7 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 5-merous, 4–5.2 mm wide; pedicels 0.2–1.6 mm long, often yellow green or red; perianth lobes cleft near to the middle, convex, elliptic, 0.9–1.2 mm long, 0.9–1.1 mm wide, often yellow green or red, strigillose in outside; filaments linear, inflexed, 1.6–2.2 mm long, yellow green, anthers basifixed, 0.7–1 × 0.7–0.9 mm, white; ovary rudimentary, clavate; pistillate flowers 2.6–3.3 mm long, sessile; perianth tubes rhomboid to obovoid, 1.3–1.7 × 0.6–1 mm, often yellow green or red, scabrous; necks 2-lobed; styles 1, linear, plumose, 0.8–2 mm long, often white or red, stigma linear. Infructescences glomerules loose at fruiting, 3.6–5.3 mm wide. Achenes 50–114 per a glomerule, rhomboid to obovoid, winged, 1.3–2 × 1.1–1.7 mm, base cuneate.
Phenology: Flowering June to September, fruiting September to November.
Chromosome number: 2n = 28 (Okabe, 1963; Yahara, 1983b).
Distribution: China, Japan, and Korea (all provinces) (Jo, 2023).
Habitat: Forest margins, mountain streams, and shady or sunny places.
Representative specimens examined: KOREA. Chungcheongbuk-do: Cheongju-si, Mt. Seondusan, 4 Jun 2021, H.J. Jo et al. HJ210604-001, 002 (ANH). Chungcheongnam-do: Cheongyang-gun, Mt. Chilgapsan, Naengcheon Valley, 9 Jun 2016, H.J. Jo et al. HJ160609-004 (ANH). Daegu-si: Dalseong-gun, Mt. Choejeongsan, 4 Oct 2019, H.J. Jo et al. HJ191004-002 (ANH). Gyeongsangbuk-do: Andong-si, Bukhu-myeon, Mt. Hakgasan, 10 Aug 2016, H.J. Jo et al. HJ160810-001 (ANH). Gyeonggi-do: Gapyeong-gun, Mt. Eobisan, Eobi Valley, 20 May 2022, H.J. Jo et al. HJ220520-003 (ANH). Gyeongsangnam-do: Hapcheon-gun, Mt. Gayasan, 28 Jul 2016, H.J. Jo et al. HJ160728-004 (ANH). Gangwon-do: Jeongseon-gun, Mt. Gariwangsan, 21 Jun 2016, H.J. Jo et al. HJ160621-002, 003 (ANH). Jeollabuk-do: Jangsu-gun, Mt. Jangansan, Deoksan Valley, 17 Aug 2016, H.J. Jo et al. HJ160817-001 (ANH). Jeju-do: Jeju-si, Aewol-eup, Musucheon Stream, 27 Jul 2016, H.J. Jo et al. HJ160727-004, 005 (ANH). Jeollanam-do: Gurye-gun, Pia Valley, 2 Sep 2019, H.J. Jo et al. HJ190902-001 (ANH).
Taxonomic note: The recent taxonomic treatment of B. paraspicata is based on a review of its identity, nomenclature, and morphological characteristics (Jo et al., 2021). Boehmeria paraspicata can be differentiated from B. gracilis by its ovate to broadly ovate middle leaves, serrate-dentate leaf margins becoming larger distally, and caudate or narrowly acute apex of leaves (Figs. 14, 15). It can be distinguished from B. spicata by its habit and leaf shape and size (Figs. 13, 14).
12. Boehmeria gracilis C. H. Wright, J. Linn. Soc., Bot. 26: 485, 1899.—TYPE: CHINA. Hubei, Patung, Ichang, May 1888, A. Henry 4692 (lectotype: K, photo!, designated by Jo et al., 2021); Hubei, 1885–1888, A. Henry 4692 (syntype: GH, photo!); Hubei, Patung, Ichang, May 1888, A. Henry 4728 (syntype: K, photo!); Hubei, Changlo, Mar 1889, A. Henry 6258 (syntype: K, photo!) (Fig. 15).
B. tricuspis var. unicuspis Makino ex Ohwi, Fl. Jap. 441, 1953.
Korean name: Top-geo-buk-kko-ri (톱거북꼬리: Cho, 2018; Jo et al., 2021).
Subshrubs monoecious or dioecious. Stems erect to descending, 0.5–1.3 m tall, 1.5–3.2 mm in diam., branches shallowly sulcate, yellow green or red, sparsely strigillose or sub-glabrous; piths not hollow; woody stems brown, glabrous, barks vertical-crack. Leaves pairs subequal in size; stipules caducous, oblong-lanceolate, 7.2–12.6 × 1.9–2.9 mm, yellow green or pale red, sparsely strigillose on the abaxial surface and vein; petioles 1.1–9 cm long, 0.6–1.9 mm in diam., red or green, sparsely strigillose; middle leaf blades elliptic, broadly elliptic, ovate or broadly depressed ovate, 3.8–13.7 × 3.3–10.6 cm, base cuneate, broadly cuneate, or sub-truncate, margin serrulate-dentate, uniform to gradually subequal distally, teeth 7–15 on one side, apex unlobed, short caudate or cuspidate, adaxial surface green, sparsely strigillose, densely punctiform lithocysts with cystoliths, midvein convex, abaxial surface yellow green, sparsely strigillose along midvein, densely uncinate bristle along veinlets, texture often thin membranous or chartaceous. Inflorescences axillary, spicate with glomerules; staminate inflorescences often unbranched or rarely branched on middle part of stem, 15.5–17.2 cm long; pistillate inflorescences 7.7–18.1 cm long, glomerules loosely at flowering. Flowers unisexual; staminate flowers 4-merous, rarely 3-or 5-merous, 3.1–5.4 mm wide; pedicels 0.2–1.2 mm long, often red or yellow green; perianth lobes cleft nearly to the middle, convex, elliptic, 0.9–1.2 × 1–1.2 mm, often red or yellow green, strigillose; filaments linear, inflexed, 1.7–2.5 mm long, yellow green, anthers basifixed, 0.7–1.3 × 0.8–1.4 mm, white; ovary rudimentary, clavate; pistillate flowers 1.6–4 mm long, sessile; perianth tubes rhomboid to obovoid, 0.7–1.4 × 0.4–1.6 mm, often red or yellow green, scabrous; necks 2-lobed; styles 1, linear, plumose, 1–3.1 mm long, often red or white, stigma linear. Infructescences glomerules loose at fruiting, 3.2–5.6 mm wide. Achenes 69–167 per a glomerule, rhomboid to obovoid, winged, 1.4–3.5 × 0.9–2.8 mm, base cuneate.
Phenology: Flowering June to September, fruiting September to November.
Chromosome number: 2n = 28 (Yahara, 1983b).
Distribution: China, Japan, and Korea (all provinces except Jejudo and Ulleungdo Island) (Jo, 2023).
Habitat: Forest margins, mountain streams, and shady or sunny places.
Representative specimens examined: KOREA. Chungcheongbuk-do: Danyang-gun, Mt. Sobaeksan, Cheondong Rest Area, 26 Jun 2020, H.J. Jo et al. HJ200626-002 (ANH). Chungcheongnam-do: Cheonan-si, Mt. Gwangdeoksan, Gwangdeoksa Temple, 12 Sep 2016, H.J. Jo et al. HJ160912-001 (ANH). Gyeongsangbuk-do: Bonghwa-gun, Mt. Baebawisan, 22 Jul 2019, H.J. Jo et al. HJ190722-003, 004 (ANH). Gyeonggi-do: Gapyeong-gun, Mt. Hwaaksan, 2 Aug 2016, H.J. Jo et al. HJ160802-007–012 (ANH). Gangwon-do: Inje-gun, Mt. Bangtaesan, 25 Aug 2018, H.J. Jo et al. HJ180825-002 (ANH). Jeollabuk-do: Jangsu-gun, Mt. Jangansan, Deoksan Valley, 17 Aug 2016, H.J. Jo et al. HJ160817-002 (ANH). Ulsan-si: Ulju-gun, Sangbuk-myeon, Mt. Baegunsan, 11 Sep 2016, H.J. Jo et al. HJ160911-001 (ANH).
Taxonomic note: Boehmeria gracilis has recently been reported as an unrecorded species in Korea by Jo et al. (2021). This species is distinguished from B. spicata by its subshrub, elliptic, broadly elliptic, ovate or broadly depressed ovate middle leaves, serrulate-dentate margin of leaves that uniform to gradually subequal distally, short caudate or cuspidate apex of leaves (Figs. 13, 15).
13. Boehmeria silvestrii (Pamp.) W. T. Wang, Acta Phytotax. Sin. 20: 204, 1982; B. platanifolia var. silvestrii Pamp., Nuovo Giorn. Bot. Ital. n. s. 22: 278, 1915; B. japonica var. silvestrii (Pamp.) Friis & Wilmot-Dear, Blumea 58: 191, 2013.—TYPE: CHINA. Hubei, 1912, P.C. Silvestri 4070 (lectotype: FI, photo!, designated by Jo et al., 2021), 4070a (isolectotype: FI, photo!, designated by Jo et al., 2021) (Fig. 16).
B. tricuspis (Hance) W. T. Wang, Acta Bot. Yunnan. 3: 410, 1981, nom. illeg., later homonym.—TYPE: CHINA. Prov. Shannxi, Fuping, 18 Jun 1952, K.T. Fu 4616 (holotype: ?, not seen).
Korean name: Cham-geo-buk-kko-ri (참거북꼬리: Cho, 2018; Jo et al., 2021).
Subshrubs monoecious or dioecious. Stems erect to descending, 0.8–1.4 m tall, 1.9–3.6 mm in diam., shallowly sulcate, yellow green or red, sparsely strigillose or sub-glabrous; piths not hollow; woody stems brown, glabrous, barks vertical-crack. Leaves pairs subequal in size; stipules caducous, narrowly triangular, 8.6–13.1 mm long, 1.7–3.2 mm wide, yellow green, sparsely strigillose on the abaxial surface and vein; petioles 4.3–13.2 cm long, 0.9–1.5 mm in diam., yellow green or red, sparsely strigillose; middle leaf blades 5-angled ovate, orbicular-ovate, or broadly ovate, 8.6–13.6 × 8.1–13.1 cm, base broadly cuneate or sub-truncate, margin serrate-dentate, gradually larger distally, teeth 7–11 on one side, apex 3- or 5-lobed, caudate, adaxial surface green, sparsely strigillose, densely punctiform lithocysts with cystoliths, midvein convex, abaxial surface yellow green, sparsely strigillose along midvein, densely uncinate bristle along veinlets, texture often thin membranous or chartaceous. Inflorescences axillary, spicate; staminate inflorescences often unbranched or rarely branched on middle part of stem, 9.6–15.6 cm long; pistillate inflorescences 8.7–22.3 cm long, glomerules loose at flowering. Flowers unisexual; staminate flowers 4-merous, 2.6–4.4 mm wide; pedicels 0.2–1.2 mm long, often yellow green or red; perianth lobes cleft nearly to the middle, convex, elliptic, 0.8–1.1 × 0.8–1 mm, often yellow green or red, strigillose; filaments linear, inflexed, 1.3–1.8 mm long, yellow green, anthers basifixed, 0.6–0.9 × 0.6–0.9 mm, white; ovary rudimentary, clavate; pistillate flowers 3.3–4.4 mm long, sessile; perianth tubes rhomboid to obovoid, 1–1.2 × 0.7–1.5 mm, often yellow green or red, scabrous; necks 2-lobed; styles 1, linear, plumose, 1.7–3 mm long, often white or red, stigma linear. Infructescences glomerules loose at fruiting, 3.4–4.9 mm wide. Achenes 56–142 per a glomerule, rhomboid or obovoid, winged, 1.5–2.3 × 1–1.4 mm, base cuneate.
Phenology: Flowering June to September, fruiting September to November.
Chromosome number: 2n = 42 (Okabe, 1963).
Distribution: China, Japan, and Korea (Gyeonggi-do, Gangwon-do, Chungcheongbuk-do, Jeollabuk-do, and Gyeongsangbuk-do) (Jo, 2023).
Habitat: Forest margins, mountain streams, and shady or sunny places.
Representative specimens examined: KOREA. Chungcheongbuk-do: Danyang-gun, Mt. Sobaeksan, Cheondong Rest Area, 26 Jun 2020, H.J. Jo et al. HJ200626-001 (ANH). Daegu-si: Dalseong-gun, Mt. Choejeongsan, Daewonsa Temple, 4 Oct 2019, H.J. Jo et al. HJ191004-001 (ANH). Gyeongsangbuk-do: Bonghwa-gun, Mt. Biryongsan, 17 Jul 2019, H.J. Jo et al. HJ190717-002, 003 (ANH). Gyeonggi-do: Hanam-si, Mt. Namhansan, 21 Oct 2022, H.J. Jo et al. HJ221021-006 (ANH). Gangwon-do: Jeongseon-gun, Mt. Hambaeksan, Jeokjoam Temple, 6 Aug 2022, H.J. Jo et al. HJ220806-001 (ANH); Pyeongchang-gun, Mitan-myeon, Mt. Baegunsan, 2 Jul 2021, H.J. Jo et al. HJ210702-001 (ANH); Yeongwol-gun, Ikki Valley, 15 Sep 2022, H.J. Jo et al. HJ220915-001 (ANH).
Taxonomic note: This taxon and B. tricuspis (=B. platanifolia) are commonly recognized as same or are confused owing to a shared characteristic, the 3-lobed apex of leaves, not found in related taxa (Makino, 1940, 1961, 1989; Ohwi, 1953, 1965; Kitamura and Murata, 1961; Im, 1996; Lee, 1996a, 1996b; Lee, 2003; Tateishi, 2006; Liang, 2009; Wilmot-Dear and Friis, 2013; Kim, 2018). However, Jo et al. (2021) recently revealed that the two taxa are distinct species based on their habit, inflorescence shape, and trichomes on the stems, abaxial leaf surface, perianth of staminate flowers, and achenes (Figs. 1–3, 9, 16).
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