Cheirostylis barbata Q. Liu & X. F. Wu, 2020

Wu, Xun-Feng, Liu, Qiang, Li, Jin-Long, Tang, Zong-Ying & Xing, Xiao-Ke, 2020, Cheirostylis barbata, a new species Orchidaceae (Goodyerinae) from Yunnan, China, Phytotaxa 436 (3), pp. 293-297 : 293-296

Cheirostylis barbata Q. Liu & X. F. Wu , sp. nov. (流fiẍ柱兰) ( Figure 1 , 2 )

Type: — CHINA. Yunnan: Shilin County, Guishan National Forestry Park, limestone forest, 2017 m in elevation, 21 March 2019, Q. Liu 690 (holotype, HFTC!)

Diagnosis: — Cheirostylis barbata is similar to C. griffithii in their vegetative as well as floral morphology. However, Cheirostylis barbata can be easily distinguished from latter in having densely villous inflorescence; flowers larger with floral bracts 12–14 mm long, significantly longer than ovary; deeply laciniate lobes of epichile with 7–9 divisions, each laciniae randomly oriented, 6.0– 7.5 mm long; hypochile containing 2 callus, each callus 4-toothed in former, against, sparsely villous inflorescence, flowers smaller with floral bracts 7.0–9.0 mm long, shorter than or as long as ovary; lobes of epichile deeply laciniate with 8–10 divisions, flabelliform, each laciniae 1.0– 3.5 mm long, hypochile containing 2 comb-like calli, each callus 8- or 9-toothed in latter.

Terrestrial herbs. Plants 7.5-10 cm tall. Rhizome creeping, tuberous, cylindrical, 2.5–3.0 cm long, 5.0–7.0 mm in diameter, roots arising from rhizome internodes. Stem erect, 1.4–2.0 cm long. Leaves 3–4, ovate, 1.0–1.2 × 0.5–0.9cm, often withered at anthesis, congested to rarely well-spaced, apex acuminate. Inflorescence 7.2–9.0 cm, densely villous, with 2 or 3 sterile bracts; rachis 1.2–1.8 cm, 5–8-flowered; floral bracts lanceolate, glabrous, 12–14 × 4.5–5.0 mm, significantly longer than ovary. Flowers whitish, opened, ovary 6.0–7.0 mm, pubescent. Sepals 4.5–5.0 × 1.5–1.8 mm, basal 1/2 connate and forming a tube, outer surface sparsely pubescent; free apical lobes acute, slightly reflexed. Petals obliquely falcate, glabrous, 5.0–5.2 × 1.5–1.6 mm, apex obtuse. Lip 9.0– 9.5 mm long, longer than sepals, 3-partite; hypochile slightly saccate, ca.1.8 × 1.6 mm, containing 2 callus, each callus 4-toothed; mesochile 1.0–1.1 × 1.2–1.4 mm; epichile orbicular, 6.8–7.0 × 9.5–10 mm, base with 2 yellow-green blotches, 2-lobed; lobes deeply laciniate with 7–9 divisions, each division 6.0– 7.5 mm, randomly oriented.. Column ca. 1 mm, stelidia straight, linear, ca. 2 mm, ca. as long as rostellum arms; anther ovoid, ca. 2× 1 mm; pollinarium ca. 2.0 mm long, rostellum arms spatulate, ca. 2 mm long.

Etymology: —The specific epithet refers to the significantly long and randomly oriented laciniate margin of lip which gives look of a tufted white hairs in from of the flower and hence the name “ barbatus ” is attributed to it.

Distribution and habitat: — Cheirostylis barbata is terrestrial species that grows in limestone forests, which is dominated by Cyclobalanopsis glaucoides Schottky (1912:657) ( Fagaceae ), Cyclobalanopsis delavayi (Franchet) (1912: 158) Schottky (1912: 158) ( Fagaceae ), Pistacia weinmanniifolia J. Poisson ex Franchet (1886: 467) ( Anacardiaceae ), as well as some of other orchid species, including Goodyera schlechtendaliana H. G. Reichenbach (1850: 861) , Malaxis monophyllos (Linnaeus) (1753: 947) Swartz (1800: 234), Gastrochilus formosanus ( Hayata ) (1911: 336) Hayata (1917: 78).

Phenology: —Flowering and fruiting from March to April, and leaf sprouting in May.

Additional specimens examined: — CHINA. Yunnan: Shilin County, Guishan National Forestry Park, limestone forest, 2017 m in elevation, 21 March 2019, Q. Liu 690 (paratype, HFTC!).

Conservation status: — Cheirostylis barbata was collected in Guishan National Forestry Park, Shilin County, Yunnan Province, China. Until now, only one population, consisting of ca. 50 mature individuals have been seen. However, the habitat is well protected and similarity limestone forests are distributed around type location on a larger landscape. Therefore, we expect that more populations and individuals could be found in the adjoin areas after further field investigation. We suggest that the current conservation status of this new species to be Data Deficient following the latest IUCN guidelines ( IUCN 2019)

Note: —Morphologically, Cheirostylis barbata is similar to C. griffithii Lindley (1857: 188) in their vegetative as well as floral morphology. However, Cheirostylis barbata can be easily distinguished from latter by having densely villous inflorescence in former (against sparsely villous in latter); large flowers with floral bracts 12-14 mm long, significantly longer than ovary (against smaller flowers with floral bracts 7.0–9.0 mm long, shorter than or as long as ovary in latter); lobes of epichile deeply laciniate with 7–9 divisions, each laciniae, 6.0– 7.5 mm long and randomly disoriented in former (against lobes of epichile deeply laciniate with 8–10 flabelliform divisions, each division 1.0– 3.5 mm long in latter); hypochile containing 2 callus, each callus 4-toothed in former (against hypochile containing 2 comb-like calli, each callus 8- or 9-toothed in latter).

Figures

FIGURE 1. Cheirostylis barbata. A. Habitat. B. Inflorescence. C. Plant with leaf. D. Lateral and front view of labellum. E. Floral bract, dorsal sepal, petals, lateral sepals (from left to right). F.Anther cap. G. Pollinarium. H. Column. I. Rhizome. (Photographed by Q. Liu)

FIGURE 2. Seed micro-morphology (SEM)of Cheirostylis barbata (Photographed by X. K. Xing).