pok-radbundit

125 Chayan Picheansoonthon and Pornpimol Wongsuwan «“√ “√ √“™∫— ≥±‘ µ¬ ∂“π ªï ∑’Ë ÛÛ ©∫— ∫∑’Ë Û °.§.-°.¬. ÚııÒ This Thai endemic species was described in 1995 based on the specimen collected from Ko Samui in Changwat Surat Thani (Sirirugsa & Larsen, 1995). The plant can be recognized with the following char- acters: bracts oblong, not imbricate, 3-4 flowered, and densely hairy; calyx tube hairy, twice as long as the bract; staminodes oblanceolate- cuneate, apex acute; labellum obovate-cuneate, shortly clawed, deeply bilobed; and ovary densely hairy. [Figs. 16 & 17] 15. H. speciosum Wall. in Roxb., Fl. Ind. 1 (1820) 13. Type: Gomez in Wallich Cat. No. 6550, India, Silhet (lectotype K) This taxon can be found on limestone rocks in open grassy forest of Doi Chiang Dao (Changwat Chiang Mai). The recognition characters for this species are the 2-flowered bracts, hairy calyx tubes, linear-oblanceolate staminodes, oblong-cuneate labellum with round or irregularly crenate or emarginate apex, stamen twice as long as the labellum, and hairy ovary. [Fig. 18] 16. H. spicatum Buch.-Ham. ex Sm., Ress Cyclop. 17 (1811) 8. Type: to be selected This Himalayan species can be found in open grassy forests on high mountain peaks of northern Thailand. It is common on Doi Luang, the highest peak of Doi Chiang Dao Wildlife Sanctuary in Changwat Chiang Mai. The folded 1-flowered bracts and the shorter-than-label- lum orange stamen are the major distinguish characters of this plant. [Figs. 19 & 20] The linear staminodes of this species are white with orange base, while the labellum of the same color pattern is clawed, obovate or elliptic, and deeply divided. The other variety, H. spicatum Buch.-Ham. ex Sm. var. acuminatum (Rosc.) Wall., with laxer and fewer-flowered inflorescences and longer corolla tubes, lobes, staminodes and labella, was also found in north Thailand. [Fig. 21] 17. H. stenopetalum Lodd., Lodd. Bot. Cab. 20 (1833) t. 1902. Type: to be selected This is another Indian taxon distributed throughout the Hima- layan, northern Myanmar and Thailand. The plant is one of the Hydechium species which can grows very tall (1.5-2.5 m). In Thailand, it can be found at Doi Inthanon, Doi Chiang Dao, Doi Suthep, Doi Phahom Pok (Changwat Chiang Mai). The inflorescence of this species is long with a hairy rachis. The bracts are not imbricate, each subtends 8-11 flowers. The flower has densely hairy calyx tube, white oblanceolate-linear staminodes, white long-clawed deeply-lobed obovate labellum, stamen with filament twice as long as the labellum and ca. 1 cm anther, and densely brownish hairy ovary. [Fig. 22] 18. H. thaianum Mokkamul & Picheans., Folia malaysiana 6 (2005) 18 (-19, 21, 24-25); figs. 1, 3-6. Type: Mokkamul & Picheansoonthon 588, Thailand, Chiang Mai, Doi Inthanon (holotype BKF, paratypes SING, PEK) This species was recently described by the first author and his student (Picheansoonthon and Mokkamul, 2006). It can be easily distinguished from other species occurring in Thailand by its glabrous habit; laxly few-flowered inflores- cence with 1-2 flowers in each bract; labellum shorter than staminodes, divided to or almost to its base to form linear halves; sta- men twice as long as the labellum; and the glabrous ovary. The bracts