Platanthera deergongensis X.H. Jin, Jian W. Li & D.L. Lin

Lin, Dongliang, Zhang, Liyue, Ye, Chao, Li, Jianwu & Jin, Xiaohua, 2024, Two new species of Platanthera (Orchidaceae, Orchidoideae) from Xizang, China, Phytotaxa 646 (2), pp. 203-212 : 206-207

Platanthera deergongensis X.H. Jin, Jian W. Li & D.L. Lin , sp. nov.

Type: — CHINA. Xizang Autonomous Region, Linzhi City, Motuo County, Beibeng Township , Deergong Village , humid alpine conifer forests, elev. 2800 m, 7 August 2023, Xiaohua Jin, Jianwu Li, Dongliang Lin, Chao Ye & Haixia Wen 41204 (holotype PE!) .

Diagnosis: —Morphologically, Platanthera deergongensis is similar to P. contigua , but differs from it by large plants, reflexed petals, white lip, connective obtuse to truncate and not protruding from the anther.

Description: —Terrestrial to epiphytic plants, plants 10–35 cm tall. Rootstock cylindric, stout, ca. 4 mm in diameter. Stem erect, terete, with 2 tubular sheath at the base. Leaf 1, basal elliptic, ca. 9 × 5cm, basally contracted into a petiole-like amplexicaul sheath, apex obtuse, adaxially green, with bottle-green reticulate veins, abaxially pale green, midvein prominent; foliaceous sterile bracts 3, lanceolate, 1.5–2.5 × 0.5–0.8 cm, apex acute. Inflorescence densely 30-flowered, secund; rachis 5–13 cm long; floral bracts lanceolate, longer than ovary, 1.2 × 0.3 cm, apex acute. Flowers white; ovary twisted, slightly arching, fusiform, ca. 1 cm long including pedicel. Dorsal sepal ovate-lanceolate, ca. 6 × 2mm, 1-veined, lateral margins erect, base concave, apex obtuse; lateral sepals linear-lanceolate, ca. 5 × 1mm, 1-veined, apex obtuse, slightly reflexed. Petals ovate-lanceolate, ca. 4 × 1mm, slightly falcate, 1-veined, apex obtuse, reflexed; lip white, linear-oblong, ca. 5 × 1mm, decurved, green dilated at base, apex obtuse; spur oblongcylindric, white, slightly arching, half ovary as long, ca. 4 × 2mm, apex obtuse-rounded, contracted at neck. Column ca. 1.5 mm long; anther erect, 2-locular, obovate, ca. 1 mm long, parallel; connective obtuse to truncate, not protruding from anther, not obviously; rostellum very small; lateral appendages ovate to oblong; pollinia obovate, ca. 0.3 × 0.2 mm, with short caudicle; viscidia elliptic, ca. 0.2 × 0.1 mm; stigma 1, reniform, raised below the rostellum.

Etymology:— The name “ deergongensis ” refers to the type locality of the new species, Deergong village, Linzhi, Xizang, China.

Distribution and habitat:— The new species is only distributed in Deergong Village, Beibeng Township, Motuo County, Linzhi City, Xizang Autonomous Region, China, terrestrial under humid alpine conifer forests.

Phenology:— Flowering from August to September.