Medium sized epiphyte. Pseudobulbs much-reduced or absent. Leaves oblong, to 50 cm long, to 10 cm wide. Flowers few to many, to 6 cm wide, yellow or greenish with heavy brownish spots, labellum pink with a purplish base; summer. Sepals unequal, laterals longer than dorsal. Petals slightly narrower than sepals, spoonshaped. Labellum 3-lobed, side lobes small, midlobe spoon-shaped, callus purple.

S America.

O. pumilum Lindl. from S America is a small epiphyte with minute compressed pseudobulbs and short panicles of many small yellow and brown flowers.

Source: Jeanes, J. (2005). Orchidaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.