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148 The Journal of the Royal Institute of Thailand Volume III - 2011 148 Taxonomic Revision of the Genus Hedychium J. Ko.. nig (Zingiberaceae) in Thailand (Part I) Epiphytic, perennial herb. Pseudostems 0.2-0.6 cm high, leaf sheaths green, margin red, bladeless sheaths 2-3. Ligule ovate, 5.2-5.6 cm long, apex acute, membranous, sparsely hairy, pale greenish. Leaves subsessile or petiolate, 1.5-3.0 cm long; blade elliptic-oblong, 28.0-42.0 by 9.0-12.7 cm, base cuneate, apex acute or shortly acuminate, margin slightly undulate, upper surface glabrous, lower surface hairy along the midrib. Inflorescence a terminal spike, erect, 10.3- 14.0 cm long, peduncle 7.5-10.5 cm long; bracts imbricate, overlapping, broadly ovate, 4.5-5.0 by 4.7-6.3 cm, apex rounded or acute, margin free to the base, sparsely hairy, green with reddish margin, each subtending a cincinnus of 1-2 flowers; bracteoles tubular, 3.5-4.0 by 1.8-2.4 cm, apex acute, split on one side to a depth of ca . 1.5 cm, hairy, reddish. Flowers white; calyx tube slender, 5.5- 6.8 cm long, apex acute, glabrous; corolla tube narrow, 9.0-11.5 cm long, 3- lobed, lobe linear, 4.0-4.5 by ca. 0.1 cm; lateral staminodes narrowly lanceolate- oblong, 4.5-5.5 by ca . 0.3 cm; labellum shorter than staminodes, obovate, 3.8- 5.1 by 1.0-1.6 cm, deeply divided, base attenuate into a 0.7-2.3 cm claw; filament ca . 5 cm long, anthers dorsifixed, 0.8-1.0 cm long, base divaricate, yellowish; ovary green, glabrous, ca . 3 by 4 mm, 3-loculed, placentation axile; epigynous glands 2, ca . 3 mm long, yellowish; stigma densely ciliate, greenish. Fruits broadly ellipsoid to broadly ovoid, 3.5-4.0 by 2.3-2.50cm, trilobe, glabrous, pale reddish/greenish. Thailand.›PENINSULAR: Yala [Hala Wildlife Sanctuary, Hungus peak]. Distribution.›Peninsular Malaysia (Fraserûs Hill › Type, Camaron Highlands) Ecology.›Tropical evergreen rain forest, at the altitude of ca. 1,200 m. Phenology.›flowering April-May (recorded cultivated from plants collected on top of Hangus mountain, Changwat Yala and from living specimens in type location), fruiting May-July Vernacular name.› Note.›This species can be easily recognized by its large, broad, glabrous, overlapping bracts, long narrow staminodes and ovate-obovate deeply-bilobed labella. ACKNOWLEDGEMENT This research project is a part of the five-year project entitled çStudies on fundamental botanical knowledge and DNA fingerprints of the Thai medicinal Waané, financially supported by the Thai Traditional Medical Knowledge Fund 126-149_mac9 4/26/12, 9:15 PM 148