Odontochilus nandae Raskoti & H.Kurzweil, 2015

Raskoti, Bhakta Bahadur & Kurzweil, Hubert, 2015, Odontochilus nandae (Orchidaceae; Cranichideae; Goodyerinae), a new species from Nepal, Phytotaxa 233 (3), pp. 293-297 : 293-295

Odontochilus nandae Raskoti & H.Kurzweil sp. nov. ( figs 1–3 )

Type:— NEPAL. Western Development Region: Kaski District, Panchase forest, 2400 m, 20 August 2008, Bhakta B. Raskoti 119 (holotype KATH).

Diagnosis: This new species is close to the mycotrophic Odontochilus saprophyticus (Averyanov 2003: 141) Ormerod (2003: 141) with which it shares the lip shape but differs in having rudimentary leaves, secund inflorescences and petals with large anterior lobes.

Autotrophic herbs, 8 – 10 cm tall. Rhizome coralloid, 15 mm long, 3 – 4 mm in diameter. Stems erect, 4 – 5 cm long, lower part 3 – 4-noded, pinkish brown, with a single or occasionally 2 – 3 tiny leaves and a sterile bract above the leaves. Leaves dark green dorsally and greyish ventrally, ovate, acute, 4 – 7 × 4 – 5 mm, base shortly sheathing, brownish. Inflorescences 4 – 5 cm long; peduncle cylindric, 3 cm long, densely pubescent; rachis 2–3 cm long, with 3 – 4 secund flowers, pubescent; floral bracts elliptic-ovate, acute, concave, 4.0 – 5.0 × 2.5 – 3.0 mm, outer surface pubescent. Flowers resupinate; ovary and pedicel cylindric, slightly beaked, 7 – 10 mm long, pubescent. Sepals olive pinkish brown, pubescent on the outer surface; dorsal sepal connivent with the petals, forming a joint hood, ovate, cymbiform, obtuse, 4.0 – 5.0 × ca. 2.5 mm, 1-veined, outer surface hairy; lateral sepals spreading, oblong, oblique, obtuse, ca. 5 × 2 mm, 1-veined. Petals oblique, oblong, unequally lobed with large anterior lobes, obtuse, 4.0 – 5.0 × 1.5 – 2.0 mm, 1- veined. Lip white, T-shaped, 7 – 9 mm long; hypochile 2 – 3 mm long, 2 mm wide, with spur like ca. 2 mm deep saccate base, inside two ligulate ca. 2 mm long calli; mesochile 3 – 4 × ca. 2 mm, flanges irregularly erose; epichile 2-lobed, 4 – 5 × ca. 5 mm, lobes diverging at right angle to axis of lip, obovate, subobtuse, 3.0 – 3.5 × 2.5 – 3.0 mm, margin entire. Column ca. 4 mm long, with two lanceolate wings ca. 2 × 1 mm; anther narrowly ovoid, ca. 2 mm long; rostellum bilobed, stigma 1 mm long.

Flowering time:— August.

Distribution:— Known only from the type locality in the western development region of Nepal.

Habitat and conservation:— Terrestrial in humus-rich litter on a moist slope in shaded temperate forest at 2400

m elevation. Only one population consisting of no more than 15 plants was found, and based on the geographically restricted occurrence and the population size this species is considered as severely threatened. Overgrazing is its major threat.

Etymology:— Odontochilus nandae is named in honour of Ms. Nanda Devi Kunwar, a local conservationist from western Nepal. Forest encroachers cut off her hands while she was erecting a fence to protect a community forest. However, this incident did not stop her from continuing to contribute to conservation.

Note:— In its lip shape O. nandae is nearest to O. saprophyticus from Vietnam and China, but the latter has entire, oblong, falcate petals unlike the lobed petals of O. nandae . Furthermore, O. saprophyticus is holomycotrophic, whereas O. nandae has tiny leaves. In its habit, O. nandae is intermediate between holomycotrophic and green-leaved species (in which leaves can be up to 6 or more cm long). Odontochilus nandae also differs from O. saprophyticus in having a coralloid rhizome (in contrast, that of the latter species is cylindrical and creeping).

Figures

FIGURE 1. Odontochilus nandae. A. Habit. B. Flower. C. Dorsal sepal. D. Lateral sepal. E. Petal. F. Lip. G. Ovary and pedicel. H. Floral bract. I. Lip calli. J. Pollinia (dissected from spirit-preserved material).

FIGURE 2. Odontochilus nandae. A. Habit. B. Close up of flower (front view). C. Inflorescence.

FIGURE 3. Distribution of Odontochilus nandae in the Nepal Himalayas.