After Franz Graf von Thun (1786–1873), of Bohemia.
Terrestrial or epiphytic herbs, sympodial. Stems slightly thickened into terete, cane-like pseudobulbs, clustered, covered with papery sheaths, biennial. Leaves 2-ranked, lateral and apical, thin, bluish-green, stalkless. Inflorescences terminal racemes or clusters, drooping, with large bracts. Flowers resupinate, medium sized to large, fragrant, white or purplish. Sepals and petals similar, free, lanceolate. Labellum entire, tubular or bell-shaped at base, fringed on apical margin, 5?7-keeled, spurred at base. Column slender, winged. Pollinia 4, each deeply 2-lobed.
About 6 species from India, China, Burma and SE Asia.
Robust terrestrials with long cane-like pseudobulbs that last only 1 or 2 years, and bluish-green, 2-ranked leaves.
Source: (2005). Orchidaceae. In: . Horticultural Flora of South-eastern Australia. Volume 5. Flowering plants. Monocotyledons. The identification of garden and cultivated plants. University of New South Wales Press.
