สำนักราชบัณฑิตยสภา

128 The Journal of the Royal Institute of Thailand Volume III - 2011 128 Taxonomic Revision of the Genus Hedychium J. Ko.. nig (Zingiberaceae) in Thailand (Part I) or rounded. Leaves lanceolate-oblong or elliptic, base cuneate, apex acute- acuminate or caudate, margin entire to slightly undulate, upper surface glabrous, lower surface glabrous or pubescent. Inflorescence a terminal spike, erect, 7.4-52.3 cm, glabrous or pubescent; peduncle 1.7-21.1 cm long; bracts imbricate- elongated to visible rachis or not imbricate, rachis usually visible, apex acute or rounded, glabrous or pubescent, each bract subtending of 1-7(-11) flowers; bracteole, folded or tubular, membranous, glabrous or pubescent, shorter or longer than bract. Flowers white, yellowish to golden yellow or reddish, fragrant; calyx tubular, split on one side, apex acute to 3-dented, glabrous or pubescent; corolla tube slender or twisted, glabrous or pubescent, 3-lobed, lobes linear, apex hooded; lateral staminodes linear-oblong, oblanceolate, or elliptic; labellum ovate-elliptic, obovate or suborbicular-orbicular, base attenuate into claw, apex acute or emarginate to deeply divided; filament 0.7-7.4 cm long, shorter or longer than labellum; anther dorsifixed, base divaricate 0.3-1.8 cm long; ovary glabrous or pubescent, 3-loculed, placentation axile, epigynous glands 2; stigma densely ciliate, green. Fruits glabrous or pubescent, ellipsoid-oblong or globose. Seeds numerous, ellipsoid-oblong or globose, aril orange-reddish. KEY TO THE SPECIES 1. Bracts imbricate (rarely elongated to visible rachis) 2. Inflorescenes cylindrical or ellipsoid. Lower leaf surface glabrous or hairy along midrib 3. Anther 0.8-1cm long 4. Ovary glabrous 10. H. malayanum 4. Ovary densely brownish hairy 16. H. siamense 3. Anther 1.1-1.7 cm long 5. Flowers yellow, curl-backward 9. H. longicornutum 5. Flowers white, not curl-backward 6. Labellum elliptic, apex emarginate 6. H. ellipticum 6. Labellum obovate, apex deeply divided at base 8. H. khaomaenense 2. Inflorescenes conical-elongated to visible rachis. Lower leaf surface pubescent 5. H. coronarium 1. Bracts not imbricate, rachis usually visible 10. Flowers strictly 1 per bract 11. Flowers golden yellow 1. H. aureum 126-149_mac9 4/26/12, 9:15 PM 128