Bulbophyllum hymenochilum Kraenzl. 1905 SECTION Biflorae Garay, Hamer, & Siegrist 1994

Photo by P Jongejan

Common Name The Rheophytic Bulbophyllum [refers to its being inundated at some point in its environment]

Flower Size .24" [6 mm]

Found in Sarawak Borneo in swampy forests at elevations of sea level to 800 meters as a miniature sized, hot to warm growing epiphyte with a creeping rhizome with somewhat persistent bracts giving rise to distant, .32 to .6" [.8 to 1.5 cm] between each, ovoid, obtusely 4 angled pseudobulb carrying a single, apical, elliptic to ovate, rounded to obtuse, petiolate base leaf that blooms on an erect, peduncle to 1.28 to 2.52" [3.2 to 6.3 cm] long, provided with 3 bracts, rachis .12" [3 mm] long, simultaneously, 2 flowered inflorescence with shorter than the ovary floral bracts.

Many referrnces include B rhomifolium as a synonym, I have left them separate for now. The petals in B rhomifolium are blunt and thickened apically while in B hymenochilum they are gradually tapering to an acute apex as well as the dorsal sepal is acuminate in B rhombifolium and is not in B hymenochilum and the lateral sepals are incurved and in B rhombifolium they are wide spread and apically are split in two.

Synonyms

References W3 Tropicos, Kew Monocot list , IPNI ; Orchids of Sarawak Beeman & Wood Beaman etal 2001; Pl. Syst. Evol. 293: 73 Jaap J. Vermeulen & Hirokazu Tsukaya 2011; An assumed rheophytic orchid: Bulbophyllum rheophyton n.sp., from Borneo; A Checklist of the Orchids of Borneo J J Woods & P J Cribb 1994; Bulbophyllum of Borneo J J Verm & O'Byrne & Lamb 2008 drawing fide

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