Cheirostylis acuminata Z.L.Liu & Q.Liu, 2016

Liu, Zhi-Long, Liu, Qiang & Gao, Jiang-Yun, 2016, Cheirostylis acuminata (Orchidaceae; Cranichideae; Goodyerinae): a new species from Yunnan Province, China, Phytotaxa 247 (2), pp. 138-142 : 138-141

Cheirostylis acuminata Z.L.Liu & Q.Liu , sp. nov. (Figs. 1,2)

Cheirostylis acuminata is close to C. clibborndyeri Yu & Barretto (1976: 15) ( Barretto et al. 2011) and C. rubrifolius Lin & Lin (2009: 327) , but differs by a shorter inflorescence (2–7 cm long), fewer flowers (1–3), pubescent ovary and outer surface of sepals, acuminate apex of lip and different size and structure of seed from C. clibborndyeri and be distinguished from C. rubrifolius by not having a saccate hypochile and no keel and papillae in the hypochile.

Type:— CHINA. Yunnan: Mengla County, Mengyuan town, Paozhuqing village, limestone forest, 21°50.21 ′ N, 101°22.25 ′ E, 800 m, 7 January 2015, Liu 12 (holotype: HITBC!).

Lithophytic herbs, 4–11 cm tall. Rhizome creeping, green, tinged with brown, 2–10 cm long, with 3–9 nodes, internodes slight narrowing, at the nodes, 4.5 mm in diameter; roots hair-like, in rows along rhizome internodes. Stem erect, 1.0– 2.2 cm long, 2–5 leaves, occasionally withered at anthesis. Leaves cauline, 3–4, well-spaced, lanceolate, 1.0–2.0 × 0.5–1.2 cm, glabrous, base rounded to truncate, apex acute, adaxially pale green, marked with indistinct deeper green veins; petiole present. Inflorescence, 2–7 cm long, hairy, with 2–3 sterile bracts, 0.8–1.4 cm long, pale pink, pubescent; rachis 1–3- flowered; floral bracts lanceolate, abaxially hairy, apex acuminate, 0.7–0.9 cm long, shorter than ovary. Flowers slightly opened; ovary and pedicel pubescent, minutely papillose, 0.8 cm; sepals 5 mm long, basal about 1/2 connate and forming a tube, outer surface pubescent, base of the tube greenish, free apical lobes pink, 2 mm long; petals appressed to dorsal sepal, white, obliquely falcate, 5.5 × 1.3 mm; lip simple, white, margin entire, 5.3 × 1.8 mm, apex acuminate, extending slightly beyond sepal tube; column 3 mm long; rostellum arms elongate, 1.8 mm long; stelidia obtuse triangle, parallel to rostellum, shorter than 0.5 mm; polinarium 2.5 mm long; anther ovoid, ca. 1.3 mm; viscidium approximate to clavate, 1.6 mm long.

Distribution:— Known only from the type locality in Mengla County, Yunnan, China.

Habitat, Phenology and Ecology:— Cheirostylis acuminata occurs in a shady limestone forest valley at 800 m and creeps on damp rock surfaces. It flowers from the middle of December to the end of January. Although the new species had flowers that barely opened, the fruiting rate was high in the natural populations. Its reproductive biology needs further study.

Etymology:— Named for the lip apex with a tiny ligule.

Taxonomic notes:— Morphologically, the new species is similar to C. clibborndyeri and C. rubrifolius , but differs as noted above and below (Table 1,2).