After Lord Grey of Groby (−1836), English orchid grower and patron of horticulture.
Epiphytic herbs, sympodial, with short, branching rhizomes. Stems thickened into short spherical to ovoid pseudobulbs, usually dense, green. Leaves lateral and apical, 2 to 8, long and narrow, grass-like, pleated, stalkless. Inflorescences basal racemes, arching or pendent. Flowers resupinate, few?several, medium sized to large, yellow to green with purplish markings. Sepals dissimilar, dorsal free and hooding, laterals partly joined, free part curved and twisted. Petals broader than sepals, free, spreading. Labellum 3-lobed, attached to column foot, side lobes erect, midlobe spreading. Column long, erect, with a short foot. Pollinia 2, waxy.
About 4 species from Brazil.
Lateral sepals partly joined, the free part curved and twisted; petals almost transparent.
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.