BULBOPHYLLUM PUSTULATUM RIDL. 1903.

Found in Penninsular Malaysia and Borneo as a small sized, hot growing epiphyte with 3/4" [2 cm] spaced, somewhat flattened, cylindrical pseudobulbs enveloped by imbricating basal sheaths when arising and carrying a single, apical, ovate, acute leaf that narrows basally into a long attenuate petiole that blooms on 1 to 3 3" [7.5 cm] long 1 to 2 flowered inflorescence with flowers that open at dawn each day and close 3 hours later only to open again the next day.

Flower Size 1" [2.5 cm]

(Source: Internet Orchid Species Photo Encyclopedia)