Tên Khoa học: Cleisostoma lecongkietii Tich et Aver.Tên tiếng Anh: Tên tiếng Việt: Mật khẩu lê công kiệtTên khác:
Perennial monopodial epiphytic herb. Stem suberect, arching to pendulous 20-30 cm long, leafy throughout. Leaves broadly lanceolate, straight to slightly recurved, rigid, thick, about 10 cm long and 2 cm wide, dark green above, paler below, unequally bilobe at the apex, with short round lobes. Inflorescence pendulous, simple, (15)20-25 cm long; scape cylindrical, 10-12 cm long, with 2-3 dark brown, distant sterile bracts; rachis angled at section, (8)10-15 cm long, with (5)7-15 spirally arranged flowers. Floral bracts erect, triangular, 1-3 mm long and broad. Flowers 2-2.5 cm across, widely opening; sepals yellow with numerous red-brown stripes and spots; petals red-brown with yellow margin and median yellow stripe; lip and column dull yellow, speckled with brown-purple; operculum dark purple-brown with two lateral spots at apex. Sepals obovate, thick, blunt, concave, cucullate, 9-11 mm long, 5-7 mm wide, with many small red-brown marks arranged into 2 bands inside, fewer and smaller marks on back, lateral sepals little wider with smaller and fewer reddish marks. Petals narrowly obovate, thick, as long as sepals, 5-6 mm wide, obtuse. Lip fleshy, sub-globular, 5-6 mm across, at the base with small cavity separated by longitudinal septum, at front 3-lobed; side lobes brightly yellow, narrowly triangular, falcate, parallel, slightly curved and forward directed, 3-4 mm long, 1.5-2 mm wide at the base, obtuse; median lobe thick and fleshy, shortly broadly
conic, rounded at the apex, with 2 small erect lateral lobules and one large hemispheric callus in central part of the median lobe, continuing backward in form of 3 fleshy keels; back-wall callus insignificant, 1-1.5 mm tall, bow-shaped, placed just below column base, opposite to 3 keels of median lip lobe. Column cylindric, 5-6 mm tall, 2.5-3 mm wide, from each side at the base with 2 large concave obovate wings 3 mm long, 2 mm wide, spreading forward and surrounding viscidium and stigma hole. Anther cap large, helmet-shaped, about 3 mm long and 2 mm wide, long beaked, truncate at apex. Pollinia yellow, narrowly ovoid, 1.3-1.5 mm long, 0.5-0.6 mm wide, incompletely divided into two subequal halves; stipe stalk straight narrow, conduplicate 1.8-2.2 mm long terminated with large, 2-lobed, saddle-shaped viscidium 1.8-2 mm long and about 3 mm wide. Ovary and pedicel cylindric, ascending, glabrous, 2-2.5 cm long, 2.5-3 mm in diam., green, sometime finely purple stripped. Fruits unknown.
Etymology: Species epithet refers to the name of the famous Vietnamese botanist and professor at the University of Science, Ho Chi Minh City Vietnam National University - Dr. Le Cong Kiet.
Ecology: Epiphyte. Evergreen broad-leaved forest. 600-800 m. Fl. February - March. Very rare. Estimated IUCN Red List status - CR [A1ac; B1+2ab(i-iv); C1; D1+2].
Distribution. Vietnam: Binh Thuan (Phan Thiet), Dak Nong (Nam Nung nature reserve). Endemic.
Studied specimens (paratypes): VIETNAM: Dak Nong province, Nam Nung nature reserve, evergreen broad-leaved forest at elevation 600-800 m a.s.l., 8 March 2013, Nguyen Van Canh s.n. (LE - photo).
Note: A taxonomically isolated species, strikingly different from all its congeners in having large flowers, a massive sub-globular fleshy lip and a broad column bearing large, rectangular, concave, and forward-directed wings on its sides. The species certainly deserves segregation into a separate monotypic section or within a taxon of higher rank because of its unique floral morphology. Collectors noted a strong putrescent smell of the flowers, which possibly plays a role in pollination (by meat-flies?). The peculiar broad wings of the column form a curious funnel-like structure and, may possibly, orient the head of pollinator correctly and directly to the viscidium.