Gastrochilus wenshanensis Q. Liu, D.P. Ye & X.H. Jin

Liu, Qiang, Wu, Xun-Feng, Zhou, Shi-Shun, Li, Jian-Wu & Jin, Xiao-Hua, 2023, New species and record of Gastrochilus (Orchidaceae, Aeridinae) from China and Laos, Phytotaxa 585 (3), pp. 210-224 : 216

Gastrochilus wenshanensis Q. Liu, D.P. Ye & X.H. Jin , sp nov. (Ẋψfiffi±) ( Figure 4–5 )

Type:— CHINA. Yunnan Province: Wenshan Zhuang-Miao Autonomous Prefecture, Malipo County, Xiajinchang Village , limestone forest, 2155 m, 16 June 2016, Qiang Liu 342 (holotype: HITBC0056874!) .

Morphologically, it is similar to Gastrochilus tsii for having a pendulous and branched stem and a fleshy and glabrous epichile, but differs from the latter by the yellow-green flowers, petals oblanceolate with an acute apex, the slightly erose margin of the epichile, and the absence of purple stripes along the margin of the hypochile.

Description:— Epiphytic herbs. Stem pendulous, 12–18 cm long, with 0.4–0.6 cm internodes, slender, often branched. Leaves alternate, distichous, ovate, 1.3–1.6 × 0.4–0.7 cm; apex acuminate and unequally 2-lobed with 1 awn (young leaf). Inflorescences several, opposite to leaves, subumbellate, 4–6-flowered; peduncle 1.6–2.7 cm long, slender, upper part enlarged, lower part with 2 sheaths; floral bracts ovate-lanceolate, ca. 1.5 mm long; pedicel and ovary 3.2–4.0 mm long. Flowers yellow-green. Dorsal sepal oblong-elliptic, concave, 3.0–3.2 × 2.0– 2.2 mm, apex acute. Lateral sepals similar to dorsal sepal, 3.8–4.0 × 2.0– 2.2 mm, apex acute. Petals oblanceolate, 3.5–3.8 × 1.6–1.8 mm, apex acute. Lip with an epichile and a saccate hypochile; epichile sub-triangular, 2.5–2.8 × 5.0– 5.2 mm, fleshy, yellowish, adaxially glabrous, margin slightly erose, apex rounded; hypochile nearly cupular, with 3-ridges externally, 4.0– 4.5 mm tall, 4.0– 4.2 mm in diameter. Column stout with purple spots, ca. 1.0 mm; rostellum bilobed with acuminate apex; pollinia 2, subglobose, ca. 0.3 mm in diameter; stipe elongate, ca. 1.2 mm; viscidium elliptic, thick and bilobed; anther cap galeate with recurved–acuminate apex, 1.5 × 1.2 mm; Capsules not seen.

Distribution and ecology:— This new species occurs in Malipo County, Yunnan Province, China. It grows on the rock at altitudes from 2055 to 2155 m in the limestone broad-leaved forests. Gastrochilus wenshanensis was observed flowering from June to July in the wild.

Etymology:—Referring to the type locality, Wenshan Zhuang-Miao Autonomous Prefecture, Yunnan Province, China.

Additional specimens examined(paratype):— CHINA: Yunnan Province: Wenshan MiaoAutonomous Prefecture, Malipo County, Xiajinchang Village , limestone forest, 2055 m, 16 June 2016, Qiang Liu 375 ( HITBC 0056905 !).

Taxonomic discussion:— According to the characteristic of the long and pendulous stem, G. wenshanensis can be placed in section Microphyllae ( Tsi 1996) . However, some species were isolated from section Microphyllae by having dense hairs on the epichile, and clustered into clade V ( Liu et al. 2019). While, other species with glabrous epichile were clustered into clade IV and new species of G. tsii and G. wenshenensis should be placed in this clade.

Figures

FIGURE 4. Gastrochilus tsii (A).A-1: Plant;A-2: Inflorescence and flowers. G. distichus (B). B-1: Plant; B-2: Inflorescence and flowers. G. pseudodistichus (C). C-1: Plant; C-2: Illustration (cited from Orchids of the Sikkim-Himalaya, Plate 305); C-3: Inflorescence and flowers. G. wenshenensis (D). D-1: Plant; D-2: Inflorescence and flowers.

FIGURE 5. Gastrochilus wenshanensis Q. Liu, D.P.Ye & X.H. Jin, sp. nov. A. Habitat. B. Inflorescence. C. Flower. D–F. Front and lateral views of lip. G. Back view of Lip. H. Sepals and petals. I. Pollinarium. J.Anther cap. K. Leaves shape (located in basal, middle and apical stem from left to right).