สำนักราชบัณฑิตยสภา

The Journal of the Royal Institute of Thailand Volume III - 2011 141 Pornpimon Wongsuwan and Chayan Picheansoonthon Terrestrial, perennial herb. Pseudostems up to 2.5 m high, bladeless sheaths 4-5. Ligule oblong, 3.4-4.8 by 2.6-3.3 cm, apex rounded-emarginate, membranous, pubescent, greenish. Leaves sessile, blade lanceolate-oblong or elliptic, 41.9-50.5 by 7.5-10.0 cm, base cuneate, apex acuminate to caudate, margin entire to slightly undulate, upper surface glabrous, lower surface pubescent. Inflorescence a terminal spike, erect, up to 15 cm long, hairy; peduncle 3.0-4.8 cm long, hairy; bracts conical imbricate, obovate, 5.4-6.1 by 3.8-5.1 cm, apex rounded-acute, pubescent, green, each bract subtending of 5-6 flowers; first bracteole, folded, lanceolate, 2.7-4.1 by 2.0-2.3 cm, apex acute, membranous, pubescent, greenish-white; second bracteole, folded, lanceolate, 2.5-3.2 by 1.4- 2.2 cm, apex acute, membranous, pubescent, greenish-white; third bracteole folded, lanceolate, ca. 2.2 by 1.2-1.6 cm, apex acute, membranous, pubescent, greenish-white; fourth bracteole lanceolate, 2.0-2.1 by 0.8-0.9 cm, apex acute, membranous, pubescent, greenish-white; fifth bracteole triangular, 1.1-1.7 by 0.7-1.2 cm, apex acute, membranous, pubescent, greenish-white; sixth bracteole tubular, ca. 1.1 by 0.6 cm, apex acute, membranous, pubescent, greenish-white. Flowers yellow, fragant; calyx tubular, 4.0-4.5 by 0.5-0.6 cm, pubescent, apex 3-dented; corolla tube slender, 7.4-8.7 by 0.3-0.4 cm, 3-lobed, lobes linear, apex hooded, thorn-liked, yellow, 4.0-5.1 by 0.6-0.7 cm; lateral staminodes oblanceolate to broadly oblong-elliptic, 4.3-4.5 by 1.7-1.9 cm; labellum suborbicular, 4.0-4.9 by 3.5-3.7 cm, base attenuate into ca. 7 mm claw, white with dark yellow patch at base, apex 2-cleft, 6-7 mm; filament white, 5.4-5.6 cm long; anther dorsifixed, base divaricate, yellowish, 1.1-1.2 by 0.3-0.4 cm; ovary pubescent, 4-5 by 4-5 mm, 3-loculed, placentation axile, epigynous glands 2, slender, yellowish, ca. 5 mm long, stigma green, densely ciliate. Fruits not seen. Thailand.›Cultivated. Distribution.›Cultivated throughout tropical countries. Ecology.›Easily growing in moist areas. Phenology.›Flowering in rainy season. Vernacular name.›Maha Hong ( ¡À“Àß å ), Ta Hoen ( 쓇À‘ π ) (Northern). Note.›This variety is easily recognized by its yellow flowers with a dark yellow patch at the base of the labellum and conical imbricate bracts. var. forrestii (Diels ) Picheans. & Wongsuwan, var. nov. › H . forrestii Diels, Not. Roy. Bot. Gard. Edinb. 5: 304. 1912 [Type: China: Western Yunnan, Tali- valley, G. Forrest 4812]; › H . forrestii Diels, T.L. Wu & K. Larsen in Z.L. Wu & PH. Raven, Fl. China 24: 375-376. 2000. Figures 5E and 5F. 126-149_mac9 4/26/12, 9:15 PM 141