Thunia marshalliana Rchb.f.

Robust terrestrial. Pseudobulbs cane-like, to 1.3 m long. Leaves many, lanceolate, to 20 cm long, to 3 cm wide. Inflorescences to 30 cm long. Flowers 4-12, to 12.5 cm wide, not widely opening, white, labellum with yellow or orange markings; summer. Sepals and petals pointed. Labellum spur about 1 cm long.

Burma,Thailand and S China.

T. alba (Lindl.) Rchb. f. from India, Burma and China differs from T. marshalliana in having slightly smaller flowers and a narrower labellum with paler yellow keels.

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.