Herminium motuoensis X.H. Jin, 2017

Wang, Cheng-Wang, Yang, Bo-Yun & Jin, Xiao-Hua, 2017, Herminium motuoensis sp. nov. (Orchidaceae, Orchidoideae), a new species from Tibet, China, Phytotaxa 329 (2), pp. 197-200 : 197-200

Herminium motuoensis X.H. Jin , sp. nov., Figures 1 , 2 .

Type: — China. Tibet, Motuo , alpine grassland, 3570 m, Jin X. H. 18079 (holotype, PE!; isotypes, PE![spirit]) .

Diagnosis: Herminium motuoensis is closely related to H. coiloglossum , H. fallax and H. ophioglossoides , but differs from them in having rachis laxly few flowered, lip broadly ovate, with a large callus at base, and lateral lobes triangular pugioniform.

Description:— Plant 10–15 cm tall. Tubers globose, fleshy, ca. 0.3–0.5 × 0.2–0.4 cm. Stem erect, smooth, with a basal leaf and 2 tubular sheaths at base. Leaf oblong-elliptic, ca. 3.0–4.0 × 0.3–0.5 cm, apex acute, base contracted into amplexicaul sheath. Peduncle cylindrical; rachis 2–3 cm, laxly 5–7 flowered; floral bracts lanceolate, ca. 5.0–7.0 × 1.1 mm, apex acuminate. Flowers yellowish green; pedicel and ovary twisted; ovary, ca. 5.0–6.0 mm long including pedicel; dorsal sepal ovate, concave, ca. 1.5–1.8 × 1.0– 1.3 mm, apex obtuse,1-veined; lateral sepals obliquely ovate, concave, ca. 2.4–2.7 × 1.0– 1.5 mm, apex subacute,1-veined; petals obliquely ovate, ca. 1.9–2.2 × 0.8–1.2 mm, apex acute,1-veined; lip broadly ovate, ca. 4.0–5.0 × 1.9–2.3 mm, lacking spur, with a large callus at base, 3-lobed near middle; lateral lobes triangular pugioniform, ca. 1.9–2.2 × 0.4 mm; mid-lobe oblong, ca. 2.0–2.3 × 0.9 mm, apex obtuse. Column ca. 1.6–2.0 mm long; pollinia globose; caudicles short, viscidia involute, hornlike; rostellum triangular, broad; stigmas 2, transversely oblong, raised below the rostellum.

Distribution and Habitat:— Herminium motuoensis grows in alpine meadows with elevation of 3570 m. During our field in Tibet from 2014 to 2017, one population with around 50 plants were discovered.

Conservation status: –– Although the habitat of new species, alpine meadows along the stream, is rather common in alpine region of Motuo County, Tibet, China. However, only one population was discovered during our ten-year fieldwork in Tibet. In addition, alpine meadows in Tibet were overgrazed by yak and cattle. According to IUCN (2017), Herminium motuoensis was tentatively treated as Endangered (EN, criterion D).

Etymology:— The name motuoensis is derived from the type locality of the new species, Motuo County, Tibet.

Discussion:— Herminium motuoensis belongs to sect. Thisbe. Morphologically, Herminium motuoensis resembles H. coiloglossum Schlechter (1906:15) , H. fallax (Lindl. 1835:298) Hook. f. (1890:129) and H. ophioglossoides Schltr. (1912: 96) in morphological characters, such as peduncle cylindrical, yellowish green flowers, floral bracts lanceolate, pedicel and ovary twisted and lip 3-lobed, but it is readily to distinguish it from the latter.

Herminium motuoensis differs from H. fallax by having few flowers laxly along the rachis (vs. many flowers densely along the rachis), lip broadly ovate, with a large callus at base (vs. lip oblong, ecallose), lacking spur (vs. spur oblongclavate), lateral lobes triangular pugioniform (vs. lateral lobes oblong) and viscidia hornlike (vs. viscidia disklike) ( Table 1). Herminium ophioglossoides is distinguished from H. motuoensis in having tubers globose to ovoid, 0.1–0.2 × 0.5–1.2 cm (vs. tubers globose, 0.3–0.5 × 0.2–0.4 cm), leaves elliptic-lingulate, 2.0–9.0 × 0.5–2.5 cm, apex acute or obtuse (vs. leaf oblong-elliptic, 3.0–4.0 × 0.3–0.5 cm, apex acute), lip oblong, base deeply concave with a globose spur (vs. lip broadly ovate, with a large callus at base, lacking spur), lateral lobes linear (vs. lateral lobes triangular pugioniform), mid-lobe linear, apex acute (vs. mid-lobe oblong, apex obtuse) ( Table 1). Another species, Herminium coiloglossum differs from H. motuoensis in having floral bracts shorter than ovary (vs. floral bracts as long as ovary), lib oblong to nearly pandurate, base dilated and concave (vs. lip broadly ovate, with a large callus at base), lateral lobes triangular-falcate (vs. lateral lobes triangular pugioniform), mid lobe triangular (vs. mid lobe oblong) and viscidia ovoid (vs. horn-like) ( Table 1).

Figures

FIGURE 1. Herminium motuoensis X.H. Jin, sp. nov. A. Habitat. B. Flower, front view. Drawn by Yunxi Zhu.

FIGURE 2. Herminium motuoensis X.H. Jin, sp. nov. A. Habitat. B. Inflorescence. C. Plant. D. Flower, front view. E. Tubers. Photographed by Xiaohua Jin.