The family Onagraceae Juss. is composed of approximately 650 species worldwide (
Chen et al., 1992,
2007). The tribe Epilobieae differs significantly from the six other tribes of the family, because it has minute, heteropycnotic chromosomes (
Kurabayashi et al., 1962). The genus
Epilobium L. is one of two genera currently recognized in the tribe Epilobieae (
Solomon, 1982).
Epilobium is the largest genus in the Onagraceae (
Raven, 1976;
Solomon, 1982), consisting of ca. 150–200 species in sub-polar to tropical regions (
Raven, 1988; Hoch and Raven, 1992;
Baum et al., 1994). Species of the genus have large numbers of small, easily dispersed, tufted seeds, and are characterized by vigorous vegetative perennation (
Keating et al., 1982). Many hybrids of the genus have been reported (
Schmitz, 1988;
Krahulec, 1999;
Mckean, 1999;
Kitchener, 2003). The stigma shape in
Epilobium has served as an important taxonomic key character among species of the genus (
Chen et al., 1992,
2007;
Lee et al., 2013)
On the Korean Peninsula, ca. 6 to 16 species of
Epilobium have been recognized (
Nakai, 1909;
Chung, 1957;
Lee, 1980). More recently,
Lee et al. (2013) reported eight taxa native to the peninsula:
E. pyrricholophum (바늘꽃),
E. amurense subsp.
amurense (호바늘꽃),
E. amurense subsp.
cephalostigma (돌 바늘꽃),
E. fastigiatoramosum (회령바늘꽃),
E. glandulosum var.
asiaticum (줄바늘꽃),
E. hirsutum (큰바늘꽃),
E. palustre (버들바늘꽃), and
E. platystigmatosum (가는민바늘꽃).
On Ulleungdo Island, three species of
Epilobium have been recognized:
E. amurense subsp.
cephalostigma,
E. hirsutum, and
E. pyrricholophum (
Chung et al., 2011). Since 2005, we have surveyed the flora on Ulleungdo Island and reported a total of 487 native vascular plant taxa (422 species) and 36 endemic plant taxa on the island (
Chung et al., 2011).
Ulleungdo Island, located 120 km east of the Korean Peninsula, is a volcanic island of 73 km
2. Because of its maritime climate, many temperate deciduous plants and warm-temperate plants occur on the island, forming a distinctive flora (
Lee and Yim, 2002). In 2009, I discovered a morphologically distinct species of
Epilobium on Ulleungdo Island (
Fig. 1). It has a unique tetragonal stigma and is distinct from
E. pyrricholophum with a clavate stigma, from
E. amurense subsp.
cephalostigma with a capitate stigma, and from
E. hirsutum with a 4-lobed stigma (
Fig. 2). Other characteristics (such as height over 200 cm, relatively short [7.9–9.5 cm] lanceolate to long elliptic leaf shape, dark pink or red purple petal, and loosely villous pubescent surface) were distinguished from
E. hirsutum (
Table 1,
Figs. 1,
2). According to the stigma shape and other characters, it was conjectured that
E. ulleungensis is a hybrid between
E. hirsutum and
E. pyrricholophum or
E. amurense subsp.
cephalostigma). In the future, we will conduct karyotypic and molecular genetic studies to prove that this species is a hybrid. Therefore, presently, we described the taxon restricted to Ulleungdo Island as a new species,
E. ulleungensis J. M. Chung.
Taxonomic Treatment
Epilobium ulleungensis J. M. Chung, sp. nov. (
Figs. 1–
4).
TYPE: KOREA. Gyeongsangbukdo Province, Ulleungdo Island, 37°30′N, 130°50′ E, elev. 368 m. 4 Aug 2016, Chung J. M. JMC15101 (holotype: KH; isotypes: KH [2 sheets]).
Korean name: Ul-leung-ba-neul-kkot 울릉바늘꽃.
Diagnosis: Epilobium ulleungensis is clearly distinguished from its related taxa by its tetragonal stigma, over 200 cm tall height, decumbent stem, lanceolate to oblong leaf blade, short and dense pubescent covering on the whole plant, a large flower size, and a dark pink or red purple flower (
Figs. 2,
4).
Herbaceous perennial with clumped, leafy, basal soboles. Stem 2.2–2.4 m tall, decumbent, well-branched, pubescent with villous or tomentose trichomes. Leaves simple, opposite, sessile or clasping stem. Cauline leaves, blade lanceolate to oblong, 79–95 × 25–28 mm, base rounded, clasping, margin serrulate with 10–60 teeth per side, apex acute to acuminate, adaxial surface rarely pubescent, deep green, abaxial surface pubescent, margin serrulate or denticulate. Inflorescence terminal and axillary, solitary, ebracteate; pedicels 5–12 mm long, pubescent. Flowers erect, actinomorphic; sepals 4, fused, 8.0–12 × 2.5–3 mm, slightly keeled, lanceolate, pubescent; petals 4, dark pink to purple, 11–16 × 9–12 mm, obcordate; stamens 8, heteromorphic in lengths; filament 3.5–4.0 mm in short stamens, 5.5–7.0 mm in long stamens; anther 1.2–1.6 mm long, dehiscent along longitudinal slit; ovary inferior; style 8 mm long; stigma tetragonal, 2.0–3.0 × 2.5–3.0 mm. Fruit capsules, 2.8–6.5 cm long, pubescent. Seeds numerous, dark brown, ovoid, 9.2–40.6 mm long, surface finely papillose, chalazal collar 6.0–8.7 mm long. Flowering July to Sep, fruiting Aug to Oct.
Additional specimens examined: Korea, Gyeongsangbukdo, Ulleungdo Island, 37°30′N, 130°50′E, elev. 368 m, 22 Aug 2011, Chung J. M. JMC12781 (KH); 9 Sep 2009, Chung J. M. JMC11310 (KH).
Habitat: A population of
E. ulleungensis was found on a humid slope beside a stream in the upper part of Taeha valley on Ulleungdo Island (
Fig. 1A). There were several populations of
E. ulleungensis along the valley in the past. The number and size of the population has gradually decreased due to the agricultural road construction and farmland development. At present, the population area is ca. 3 m × 7m and its size fewer than 100 individuals because of clonal reproduction by runners sprouted from the lower part of the stem. Moreover, the population has been greatly threatened by the pressure of surrounding vegetation such as
Hovenia dulcis, Albizia julibrissin,
Boehmeria spicata, Pueraria thunbergiana,
Miscanthus sinensis var.
purpurascens,
Dystaenia takeshimana, and
Artemisia montana, etc. Therefore, a plan for
in and
ex situ conservation of the natural population of
E. ulleungensis is required
.
Distribution: Korea (Ulleungdo Island), endemic to Korea.
Etymology: The specific epithet is derived from Ulleungdo Island where this new species is located.
Key to Epilobium ulleungensis and its related taxa
1. Stem erect, less than 2 m tall. Stigma deeply 4-lobed,. ···················································· E. hirsutum (큰바늘꽃)
1. Stem erect, less than 2 m tall. Stigma entire or shallowly emarginate ······································································· 2
2. Stem decumbent, over 2 m tall. Stigma tetragonal ······································· E. ulleungensis (울릉바늘꽃)
2. Stem erect, stem less than 1.5 m long. Stigma clavate or capitate ··································································· 3
3. Leaves ovate or broadly oblong to lanceolate, sharply serrulate. Stigma clavate E. pyrricholophum (바늘꽃)
3. Leaves ovate to oblong-lanceolate, apex acute or acuminate. Stigma capitate ···········································E. amurense subsp. cephalostigma (돌바늘꽃)
ACKNOWLEDGMENTS
The author thanks Dr. Myong-Gi Chung for the helpful comments on the manuscript. This research was supported by research grants titled “The establishing Foundation to secure Sovereignty on the Traditional Knowledge of Ethnobotany in Korea (KNA1-1-11, 13-1)” and “Studies on the Conservation of Plant Species Diversity and Ecosystem of the Experimental Forest of Ulleungdo Island and Mt. Jumbongsan (KNA1-2-5, 08-5)” from the Korea National Arboretum.
Fig. 1.
Photographs of Epilobium ulleungensis J. M. Chung in its natural habitat on Ulleungdo Island. A. Habitat. B. Habit. C. Flower, front view. D. Flower, side view.
Fig. 2.
Stigma shape of four species of Epilobium. A. E. hirsutum. B. E. ulleungensis. C. E. pyrricholophum. D. E. amurense subsp. cephalostigma.
Fig. 3.
Holotype of Epilobium ulleungensis J. M. Chung.
Fig. 4.
A, A′. Habit. B. Cross section of stem. C. Cauline leaf. D. Bract. E. Sepal. F. Flower. G. Petal. H. Stamen. I. Pistil. J. Loculicidal dehiscence of capsules. K. Capsules. L. Seed.
Table 1.
Comparison of some morphological characteristics between Epilobium ulleungensis and its related species, E. hirsutum, E. pyrricholophum, and E. amurense subsp. cephalostigma.
Characters |
E. ulleungensis
|
E. hirsutum
|
E. pyrricholophum
|
E. amurense subsp. cephalostigma
|
Plant height (cm) |
|
215–250 |
25–120 (250) |
24–80 |
31–98 |
Leaf blade |
shape |
Lanceolate to oblong |
Lanceolate-elliptic to narrowly obovate or elliptic |
Ovate to broadly oblong |
Ovate to narrowly oblong |
length (cm) |
7.9–9.5 |
4.0–12 (23) |
2.1–4.6 |
3.0–9.5 |
width (cm) |
2.5–2.8 |
0.3–4.0 (5.0) |
0.7–2.0 |
0.5–2.5 |
hairs |
Villous pubescent or tomentose |
Densely villous pubescent or white tomentose |
Strigillose |
Subglabrous with strigillose |
Flower |
length (cm) |
2.1–3.2 |
1.2–1.5 |
0.9–1.4 |
0.8–1.3 |
color |
Deep-pink to red purple |
Pink to dark purple |
Pink to purple |
White, pink or rose-purple |
Petal |
length (cm) |
1.1–1.6 |
0.8–2.0 |
0.5–0.8 |
0.5–0.8 |
Sepals |
length (cm) |
0.8–1.2 |
0.6–1.2 |
0.3–0.6 |
3.3–6.1 |
width (cm) |
2.5–3.0 |
0.9–1.2 |
0.1–0.15 |
0.9–1.3 |
Pedicel |
length (cm) |
0.5–12 |
0.5–2.0 |
0.7–1.5 |
0.3–1.3 |
Style |
length (mm) |
7.8–8.2 |
5.0–9.0 |
1.5–3.7 |
1.2–2.6 |
Stigma |
length (mm) |
2.0–3.0 |
1.0–4.0 |
0.7–2.8 |
0.9–2.2 |
shape |
Tetragonal |
4-lobed |
Clavate |
Capitate or broadly capitate |
Filament length (mm) |
short stamens |
3.5–4.0 |
2.5–4.4 |
1.1–2.6 |
0.9–2.2 |
long stamens |
5.5–7.0 |
7.0–8.0 |
2.1–3.3 |
1.7–3.1 |
Capsule |
length (cm) |
2.8–6.5 |
2.5–9.0 |
2.6–6.7 |
4.2–6.7 |
Seed |
length (cm) |
0.9–1.2 |
0.8–1.2 |
1.5–1.8 |
0.8–1.0 |
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