Chrysosplenium zhangjiajieense X. L. Yu, Hui Zhou & D. S. Zhou, 2016

Liu, Hong, Luo, Jin-Long, Liu, Qiu-Yu, Lan, De-Qing, Qin, Rui & Yu, Xun-Lin, 2016, A new species of Chrysosplenium (Saxifragaceae) from Zhangjiajie, Hunan, central China, Phytotaxa 277 (3), pp. 287-292 : 287-291

Chrysosplenium zhangjiajieense X. L. Yu, Hui Zhou & D. S. Zhou , sp. nov. ( Figs. 1–3 )

Type: — China. Hunan: Zhangjiajie City, Wulingyuan District, Zhangjiajie National Forest Park, Shuiraosimen, ca. 890 m, beside the moist rock, 17 April 2015, H. Zhou & D. S. Zhou 15041709 (holotype, CSFI!; isotypes, CSFI!).Herbs perennial, 13–19 cm tall, white-colored 3–5 mm villus in the whole plant. Stolons, sterile branches 5.0–25.0 cm long, repent, leaves 4–8, alternate ; Basal leaves 3–5, fleshy, obovate, blade longer than broad, 52–105 × 37–65 mm, base cuneate, apex rounded, margin with 15–20 undulate-crenulate lobes on each side, symmetrical, adaxial surface dark green or reddish brown, obvious raised wart points on adaxial surface, abaxial surface paler color, veins bulge, petiole 10–20 mm. Cauline leaves 1, petiole 7–10 mm, blades oval to circular, 3–5 × 4–6 mm, base cuneate, apex rounded, margin 10–14 crenulate lobes, glabrous in both surface and sparsely hair in petiole. Flowering stems 1, erect, 13–15 cm long; bracteal leaves with petiole 3–12 mm, leaf blade oblong, 5–10 × 5–8 mm, sparsely white villus on both surfaces, apex acuminate, base cuneate, margin with 4–10 crenulate lobes; Inflorescence terminal; cymes 16–41 flowered. Sepals 4, papery, half erect, white, oblong, glabrous, 3–3.5 × 2.5–3 mm, not overlapping, margin entire, apex retuse. Petals and disc absent. Stamens 8, longer than sepals; filament 4–5 mm long; anther c. 0.6 mm long. Carpels 2; ovary semi-superior; styles ca. 3–4 mm long, erect. Capsule ca. 3–4 mm, apex neither truncate nor retuse; rostrums 2-3 mm. Seeds 10–30, dark brown, subovoid, 0.6 × 0.4 mm, small papillose.

Additional specimens examined (Paratypes): — CHINA. Hunan Province: Wulingyuan District, Zhangjiajie National Forest Park, Shuiraosimen , ca. 890 m, beside the moist rock, 16 March 2016, H. Zhou & D. S. Zhou 16031601 ( CSFI) ; Zhangjiajie National Forest Park, Tianzishan , 800–1000 m, along the moist gulley, 13 March 2016, H. Zhou & D. S. Zhou 16031321 ( CSFI) ; Zhangjiajie National Forest Park, Nantianmen , ca. 484 m, beside the moist rock, 15 March 2016, Hong Liu & D. Q. Lan ZJJ 20160315 06370 ( HSN) .

Chrysosplenium davidianum :— CHINA. Yunnan: Yangbi County, Liziping , 27 April 1940, R. C. Ching 01120989 ( PE!) ; Yunnan: Li-kiang Hsien , July 1935, C. W. Wang 01120985 ( PE!) ; Sichuang: Emei Mountain , 24 May 2016, D. Q. Lan EMS20160524 06642 ( HSN) .

Distribution:— Chrysosplenium zhangjiajieense is known only from Zhangjiajie, Hunan province, China.

Habitat:— The new species was found in the moist soils, nearby streams and stones, at an elevation between 400 and 1000 m. The species grows in the broad-leaved evergreen forests. The populations are usually dominated by Arisaema silvestrii Pamp. ( Araceae ), Corydalis sheareri S. Moore ( Fumariaceae ), Neomartinella violifolia (Lévl.) Pilger (Cruciferae) , Oxalis griffithii Edgeworth et Hook. f. ( Oxalidaceae ).

Phenology:— Chrysosplenium zhangjiajieense was observed to be flowering in March and fruiting in April.

Etymology:— The specific epithet refers to the type locality, Zhangjiajie City, Hunan province, where the new species was discovered.

Relationships: —The new species is similar to Chrysosplenium macrophyllum Oliver (1890:102) and C. davidianum Decne. ex Maximowicz (1890:112) in the papillose seed, stolon and obovate leaf blade, but differs by having white sepals, wrinkled pointed leaves and white-colored long villus covering the whole plant. Morphological differences between the three Chrysosplenium species is given in Table 1.

Conservation status:— Three small populations of this new species were found in Zhangjiajie National Forest Park. The total number of Chrysosplenium zhangjiajieense individuals within these three wild populations were less than 500. According to the protection status in Chinese plant red data book ( Yu 1999) and IUCN categories and criteria ( Baillie et al. 2004), we tentatively assess the conservation status of the new species to be endangered (EN). Therefore, it is very urgent to do further field studies and to stress on the conservation of this new species.

Figures

FIGURE 1. Chrysosplenium zhangjiajieense,A-B, Leaf epidermal hairs. C, Caulline leaf. D-E, Bracteal leaf. F, Flower. G, Ovary. H, Capsule.

FIGURE 2. Chrysosplenium zhangjiajieense (A, B, C, G, K, L) and its relative species. C. macrophyllum (D, E, F, H) and C. davidianum (I, J).A, Habitat of C. zhangjiajieense; B, Flowers of C. zhangjiajieense; C, Fruits of C. zhangjiajieense; D, Habitat of C. macrophyllum; E, Flowers of C. macrophyllum; F,Fruits of C. macrophyllum; G, Bracteal leaves of C.zhangjiajieense;H, Bracteal leaves of C.macrophyllum; I, C. davidianum, J, Sterile branch of C. davidianum; K-L, Sterile branch of C. zhangjiajieense (show white-colored long villus and raised wart point in basal leaves). A–H, K, L from Zhangjiajie, I, J from Emeishan, Sichuang Province; Photos by Hong Liu.

FIGURE 3. Seeds of Chrysosplenium zhangjiajieense and its compared relative species.A-C, C. zhangjiajieense; D, C. davidianum; E-F, C. macrophyllum.