Two new plant records, Alangium kurzii (Cornaceae) and Ficus racemosa (Moraceae), in Bhutan and corresponding distributions
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Abstract
Bhutan represents a biodiversity hotspot in the eastern Himalayan region, known for its unique environment and diverse plant species. This has made Bhutan a popular destination for plant enthusiasts from all over the world. Several new plant discoveries and records have been made in recent years, contributing valuable additions to scientific knowledge and the country’s botanical records. Here, we provide two new additional records of plants for the flora of Bhutan: Alangium kurzii Craib from the Cornaceae family and Ficus racemosa L. from the Moraceae family. With these additions, Bhutan now has three Alangium species and 25 Ficus species including the current records. We also present their uses and distributions in the country.
INTRODUCTION
Bhutan falls in part of the Eastern Himalayan (EH) region, where an area spans over both Palearctic and Indo-Malayan biogeographic realms. These areas, comprising Nepal, Bhutan, some parts of the Indian States, Southeast Tibet (China), and Northern Myanmar together are one of the 34 global Biodiversity Hotspots, exceptionally host rich biodiversity (Hanson et al., 2009; Banerjee and Bandopadhyay, 2016). Notably, Bhutan is located entirely within the EH region, covering 7.60% of the total EH area (Banerjee and Bandopadhyay, 2016). The country has a forest cover of 69.71% (Forest Monitoring and Information Division, 2023). Among the Districts, Samdrup Jongkhar (91.32%) and Zhemgang (93.89%) have the highest forest cover, while the Gasa District has the lowest forest cover at 20.56% (Forest Monitoring and Information Division, 2023). This extensive forest cover, combined with increased access to previously unexplored sites, has facilitated the growth in species listing as new records and discoveries continue to rise (Gyeltshen et al., 2018; Wangchuk et al., 2023).
The genus Alangium Lam. is generally found in tropical and subtropical regions of Asia, Africa, and the Pacific Islands. Alangium kurzii Craib, a subtropical species, is distributed throughout the warm temperate to subtropical regions of Southeast Asia (Eyde et al., 1969). Information on Alangium in Bhutan is limited, with the Flora of Bhutan documenting only A. chinense (Lour.) Harms and A. alpinum (C. B. Clarke) W.W.Sm. & Cave. Both species occur in the subtropical Districts of Chhukha, Mongar, Punakha, Sarpang, and Trongsa in Bhutan (Grierson and Long, 1983). The genus Ficus L. is also largely tropical, followed by subtropical and warm temperate species worldwide (Shi et al., 2014). The highest diversity is found in tropical rainforests, especially in Southeast Asia, Africa, and South America. The genus Ficus includes over 800 species (Lansky et al., 2008).
In Bhutan, 24 Ficus species have been reported (Table 1), excluding present newly found Ficus racemosa. Previous records in the Flora of Bhutan listed F. hirta Vahl, F. semicordata Buch.-Ham. ex Sm., and F. ichnopoda Miq. (Grierson and Long, 1983), which are now synonymized and accepted as F. simplicissima Lour., F. elmeri Merr., and F. pyriformis Hook. & Arn. respectively (Royal Botanic Garden, 2024). Similarly, F. oligodon Miq. and F. auriculata Lour., as well as F. gasparriniana Miq. and F. neriifolia Sm. recorded as separate species in the Flora of Bhutan (Grierson and Long, 1983), are now considered synonyms and accepted as F. auriculata and F. salicifolia Vahl, respectively (Royal Botanic Garden, 2024). Like the genus Alangium, Ficus is found in similar Bhutan’s climatic range, extending from subtropical to warm temperate regions. Alangium kurzii was initially described from the Indian subcontinent by the German botanist Wilhem Sulpiz Kurz in 1911 (Berhaman, 1994). Ficus racemosa L., described by Carl Linnaeus in Species Plantarum (1753), was based on a plate in Rheede’s Hortus Malabariucus labeled ‘Atty-Alu,’ a name from the Malayalam dialect (Linnaeus, 1753). However, due to the ambiguities in the accompanying text and figure of the plate, an epitype was designated to clarify the application of the name as currently accepted (Upadhyay and Srivastava, 2010).
Distribution of genera Alangium Lam. and Ficus L. in Bhutan.
Grierson and Long’s 1983 study included Alangium and Ficus species, but spatial distribution data was limited. To address this gap, a web-based online portal, Bhutan Biodiversity Portal (2024), housed at the National Biodiversity Center (NBC), was used to update distribution information, which is presented in Table 1.
We adapted an opportunistic field survey to collect the data during the flowering and fruiting seasons. During the field surveys, the first and fourth authors encountered species of the genus Alangium in two Districts, Pemagatshel and Mongar, which were clearly distinct from Alangium alpinum (C. B. Clarke) W. W. Sm. & Cave, and Alangium chinense (Lour.) Harms in Bhutan (Fig. 1). Instantly, the plant specimens were collected and photographed along with their natural habitats, both located within the temperate forest. Similarly, the specimens of Ficus racemosa were collected from different biomes, including tropical, subtropical, and temperate belts of Bhutan. The herbarium specimens were collected, and plants were pressed following specific protocols (Alexiades, 1996). The specimens were compared with the existing records in Flora of Bhutan on Alangium and Ficus in addition to consultation of experts in the region. The herbarium specimens were deposited in the National Herbarium (THIM23448) at the National Biodiversity Center, Serbithang, Thimphu, and a copy of each was preserved at Ugyen Wangchuck Institute for Forestry Research and Training (UWIFoRT) for future reference.
Spatial location of Ficus racemosa L. and Alangium kurzii Craib in Bhutan.
TAXONOMIC TREATMENT
Allangium kurzii Craib, Bull. Misc. Inform. Kew 1911: 60, 1911 (Fig. 2).—TYPE: Thailand. Chengmai, Doi Sootep, elev. 660 m, 2 Sep 1910, Kerr 1172 (K000704838).
New records of Alangium kurzii Craib. A: Dorsal surface of the leaf blade; B: Ventral surface of the leaf blade with immature fruit; C: Peduncle without fruits; D: Mature fruit; E: Immature fruit; F: Seeds of matured fruits.
Diacicarpium tomentosum Blume., Bijdr. Fl. Ned. Ind. 657, 1826; Marlea tomentosa (Blume) Endl. ex Hassk., Flora 27: 605, 1844; Alangium tomentosum (Blume) Hand.-Mazz., Symb. Sin. 7: 684, 1933.
Alangium handelii Schnarf., Anz. Akad. Wiss. Wien, Math. -Naturwiss. Kl. 59: 107, 1922.
Alangium umbellatum Y.C. Yang., Contr. Biol. Lab. Sci. Soc. China, Bot. Ser. 12: 135, 1942.
Alangium chungii H.L.Li., J. Arnold Arbor. 24: 448, 1943.
A medium-sized deciduous tree. Branchlets smooth or sparsely pubescent; internode 4–8 cm long. Leaves alternative; petiole 1–3 cm; blades ovate to elliptic, 8.5–17 × 5–11.2 cm, base rounded, margin entire, apex cuspidate to caudate, abaxially light green, adaxially dark green. Inflorescences 3-flowered; peduncle 3.2–5 cm, middle peduncle is shorter than other two. Petals 6–8, yellow, dark yellow, orange, or brick red, rarely white or cream-white. Stamens 6–8(−10), yellow, pubescent. Ovary 2-loculed; style white; stigma subglobal, 4-lobed. Fruits oval when matured with length 0.8–1.8 cm, dark violet to nearly black, elliptic. Seeds 5–6 mm long.
Flowering: May–June.
Fruiting: September.
Alangium kurzii is associated with Acer sikkimense Miq., Lithocarpus elegans (Blume) Hatus. ex Soepadmo, Elaeocarpus lanceifolius Roxb., Machilus edulis King ex Hook.f., Juglans regia L., Symplocos lucida Wall. ex G. Don, Acer campbellii Hook. f. & Thomson ex Hiern, Rhododendron grande Wight, Magnolia campbellii Hook. f. & Thomson, and Schima wallichii var. khashiana (DC.) Korth.
The genus of Alangium is used by the local communities for ethnobotanical purposes such as food, and woody parts for making the ploughing materials. The seeds are flavored for their pleasant taste and high-fat content. The well-seasoned woods are recognized as ploughing materials by local people due to their lightweight and durability.
Distribution: China, India, Malaysia, Myanmar, Philippines, Hainan, Laos, Indonesia, Japan, Korea, Sumatra, Thailand, Vietnam, and Bhutan.
Specimens examined: BHUTAN. Pemagatshel District, Nanong, Tokarey village, along Mukazor to Tokarey approach road 27.089238°N, 91.508325°E, elev. 2,172 m, 17 Jul 2023, Wangchuk TW002; Mongar District, Namling, Latongla along Mongar-Bumthang highway at 27.310570°N, 91.063194°E, elev. 2,714 m, 3 Sep 2023, Tshering TT013.
Ficus racemosa L. Sp. Pl. 1060, 1753 (Fig. 3).—TYPE: not designated in Rheede, Hort. Malab. 1: 43, t. 25. 1678; INDIA. Kerala, Cannanore District, Kararagog, 125 m, 26 Jan 1979, V.J. Nair 599923 (Epitype: CAL0000006985).
New records of Ficus racemosa L. A: Dorsal surface of the leaf; B: Young fruits on the trunk; C: Ripe fruits; D: Close-up view of ripe fruits.
Ficus goolereea Roxb., Pl. 1060, 1753.
Ficus glomerata Roxb., Pl. Corom. 2: 13, t. 123, 1799; Covellia glomerata (Roxb.) Miq., Lond. J. Bot. 7: 465, 1848.
Ficus trichocarpa Blume, Bijdr. Fl.Ned. Ind.448., 1825.
Urostigma leucocarpum Miq., Lond. J. Bot. 6: 576, 1847; Ficus leucocarpa (Miq.) Miq., Ann. Mus. Bot. Lugduno-Batavi 3: 285, 1867.
Covellia mollis Miq., Lond. J. Bot. 7: 466, 1848; Ficus mollis (Miq.) Miq., Ann. Mus. Bot. Lugduno-Batavi 3: 283, 1867, nom. illeg.
Ficus vesca F.Muell. ex Miq., J. Bot. Néerl. 243, 1861.
Ficus chittagonga Miq., Ann. Mus. Bot. Lugduno-Batavi 3: 228, 1867.
Ficus acidula King., Ann. Roy. Bot. Gard. Calc. 1: 176, 223, 1888.
Ficus henrici King., Ann. Bot. Gard. Calc. 1: 174, 220, 1888.
Ficus semicostata F.M.Bailey., Queensl. Agric. J. 26: 316, 1911.
A large deciduous tree growing up to 30 m high with buttressed roots; bark surface smooth, brown and latex milky; young shoots hairy and white. Leaves simple, alternate; stipules ovate-lanceolate, 10–20 mm long, pubescent and often persistent on young shoots; petiole 8–20 mm long; blades ovate, obovate, elliptic-oblong, 5–15 × 3–5.5 cm, base acute or obtuse, margin entire, apex narrowed or acute, membranous, glabrous. Flowers unisexual, peduncle 3–10 mm long. Fruits in tumorlike group on short branchlets of older stems, sometimes on leafy shoot or on older leafless branchlets, paired, reddish-orange when mature, pear-shaped, 2–2.5 cm in diam., basally tapper into a stalk, apical pore navel-like, flat; peduncle in fuiting stage ca. 1 cm; involucral bracts triangular-ovate in shape.
Flowering: May–July.
Ficus racemosa is associated with Magnolia champaca (L.) Baill. ex Pierre, Phoebe cathia (D. Don) Kosterm., Celtis timorensis Span., Oreocnide sylvatica (Blume) Miq., Garuga pinnata Roxb., Toona sinensis (A. Juss.) M. Roem., Gmelina arborea Roxb. ex Sm., Pterospermum javanicum Jungh., and Vitex doniana Sweet. Ficus racemosa differs from other Ficus species as its flowers and bears fruits in large clusters or racemes that emerge from bark around the main trunk of the tree and branches (Fig. 3). Other Ficus species, such as F. religiosa have solitary fruits or smaller clusters on the trunk and younger branches. It is one of the fastest-growing trees with large rough leaves, with the figs growing very close to the trunk or on the trunk (Wang et al., 2005). Among the 24 reported Ficus species in Bhutan, F. auriculata Lour. is the most similar to F. racemosa in terms of fruiting on the main trunk and branches. However, they differ in leaf shape: F. auriculata has broadly ovate leaves with shallowly or coarsely toothed margins, while F. racemosa bears coriaceous leaves with entire margins (Grierson and Long, 1983).
The figs are sweet and edible, and unripened fruits and leaves are consumed as vegetables and used to treat diarrhea. Additionally, leaves serve as valuable animal fodder and mulch. The bark possesses medicinal properties used in traditional Indian remedies for skin conditions. The tree is also cultivated as a host plant for lac insects (Ahmed and Urooj, 2010).
Distribution: India, China, Indonesia, Myanmar, Bangladesh, Nepal, New Guinea, Pakistan, Sri Lanka, Thailand, Vietnam, Borneo, Australia, and Bhutan.
Specimens examined: BHUTAN. Zhemgang District, Tingtibi at Tshanglajong, Yebilabtsa along Tingtibi-Nganglam Highway 27.118856°N, 90.720183°E, elev. 540 m, 9 Jun 2023, Tshering and Wangchuk TT012. They are also found in other regions: Chhukha District, Jigmechhu 26.758998°N, 89.735661°E, elev. 344 m, 7 Jul 2023; Sarpang District, Singye village 26.825005°N, 90.193775°E, elev. 421 m, 13 Jul 2023; Dagana District, Tashidingkha, lower Tashidingkha along the highway connecting Sunkosh and Dagapela, 26.935850°N, 90.038201°E. elev. 530 m, 17 Jul 2023.
The two plant species Alangium kurzii and Ficus racemosa, have been added to the Flora of Bhutan, bringing the known spatial distribution total number of Ficus species to 25 and Alangium species to three. Our study showed Alangium kurzii is found in temperate and Ficus recemosa in warm broadleaf and subtropical forests. Their distribution is expected to span throughout these forest types. Their distribution pattern in Bhutan is not adequately studied, so further survey is suggested.
Acknowledgements
We sincerely thank our esteemed field colleagues of Pemagatshel Forest Division, Mr. Chedup, Mr. Pema Wangchuk, and Mr. Sungrab Dorji, for their invaluable time and effort during the data collection. We also extend our sincere appreciation to the management of the Territorial Divisional Forest, Pemagatshel, the Ugyen Wangchuck Institute for Forestry Research and Training, and the Department of Forests and Park Services for their constant guidance and support that greatly contributed to this achievement.
Notes
CONFLICTS OF INTEREST
The authors declare that there are no conflicts of interest.