Odontochilus putaoensis X.H. Jin, L.A. Ye & A.T. Mu, 2018

Aung, Ye Lwin, Mu, Aye Thin & Jin, Xiaohua, 2018, Odontochilus putaoensis (Cranichideae, Orchidaceae), a new species from Myanmar, PhytoKeys 103, pp. 19-26 : 20-21

Odontochilus putaoensis X.H. Jin, L.A. Ye & A.T. Mu sp. nov. Figure 1

Diagnosis.

Odontochilus putaoensis is similar to O. duplex , but can be easily distinguished from the latter by having a light yellow lip composed of a bisaccate hypochile with a small, erect, blade-like and emarginate callus within each sac, a mesochile with a pair of dentate-pectinate flanges and bilobed epichile with a pair of widely diverging lobes that are erect and concave.

Type.

MYANMAR. Kachin State: Putao Township, Hponkanrazi Wildlife Sanctuary, subtropical, evergreen, broad-leaved, montane forest, 2000 m a.s.l., 20 October 2014, Xiaohua Jin et al, PT-ET 959 (Holotype, PE!).

Description.

Plants autotrophic, terrestrial, 40-60 cm tall. Stem ascending, pubescent, 2-6-leaved. Leaves dark green, ovate-lanceolate, 6-7.5 × 3.2-4 cm, attenuate at apex, blade glabrous; petiole-like base and tubular sheath ca. 2.8 cm long. Peduncle pubescent, with 1 or 2 sheathing bracts, reddish-brown, ovate-lanceolate, 12-15 × 4-5 mm, pubescent, long acuminate; rachis pubescent, sub-densely 16-flowered; floral bracts reddish–brown, ovate-lanceolate, ca. 9 × 4 mm, as long as ovary, abaxially pubescent, long acuminate at apex. Flowers resupinate; dorsal sepal forming a hood with petals, dark greenish-brown, ovate, ca. 6 × 3 mm, acute at apex, abaxially pubescent; lateral sepals greenish-brown, elliptic, oblique, ca. 8 × 4 mm, acute at apex, abaxially pubescent. Petals obliquely ovate-falcate, ca. 6 × 3 mm, membranous, glabrous; lip light yellow, T-shaped, shallowly grooved along the mid-line, ca. 1 cm long; hypochile bisaccate, sac sub-globose, ca. 2 mm in diameter, containing a low median keel and a small, erect, blade-like and apically emarginate callus on each side; mesochile ca. 4 mm long, with a pair of dentate-pectinate flanges, each flange composed of three narrow filaments, ca. 4 mm long and one broad blade-like posterior filament, ca. 3 mm long; epichile bilobed, lobes erect, diverging at obtuse angle to each other, elliptic, ca. 5 × 3 mm, margin involute and consequently resulting in concave lobes, obtuse at apex. Column ca. 1 mm long, stout; anther acuminate in front, ca. 4 mm long; pollinia 2, clavate; stigma lobes confluent; ovary and pedicel cylindric, twisted, sparsely pubescent.

Etymology.

The new species is named after Putao, the northernmost town of Myanmar, near which it was discovered in a vast area of undisturbed mountain forest.

Distribution and habitat.

Odontochilus putaoensis grows in shaded and damp humus in humid, broad-leaved, evergreen forest, at an elevation of about 1500-2000 m. At present, O. putaoensis is only known from the type locality.

Conservation status.

Least Concern (LC). Odontochilus putaoensis was collected in the Hponkanrazi Wildlife Sanctuary, Putao Township, Kachin State, northern Myanmar. Until now, only one population, consisting of ca. 200 individuals, has been discovered in the vast reserve of 2704 km2. As there is no threat currently affecting the quality of its habitat and there is also a considerable number of mature individuals, the species is here preliminarily assigned a status of Least Concern (LC) according to the guidelines for using the IUCN Red List Categories and Criteria ( IUCN Standards and Petitions Subcommittee, 2017).

Figures

Figure 1. Odontochilus putaoensis X. H. Jin, L. A. Ye & A. T. Mu. A Habit of Odontochilus putaoensis B Front view of flower, showing lip epichile with a pair of erect and concave lobes C Hypochile of Odontochilus putaoensis, indicating small, erect, blade-like, emarginate callus within each sac D Dissected flower, showing pedicel and ovary, column, sepals, petals, lip and a pair of clavate pollinia E Dorsal view of flower, showing dorsal sepal forming a hood with petals. Photographed by X. H. Jin.