Apostasia wallichii

Apostasia wallichii is a terrestrial, tuberous, evergreen herb, scarcely recognisable as an orchid. It has wiry, branched roots with fleshy, warty projections and an erect, fibrous stem with many grass-like leaves arranged in whorls along it. The leaves are dark green, thin and leathery 100–200 mm (4–8 in) long and up to 1 mm (0.04 in) wide. Between five and forty star-like, yellow flowers, 8–10 mm (0.3–0.4 in) wide are arranged on branched flowering stems 50–100 mm (2–4 in) long and arising from leaf axils. The three sepals and three petals are all similar in size (4–6 mm (0.16–0.24 in) long, 1–1.5 mm (0.04–0.06 in) wide), shape (narrow triangular) and colour. Flowering occurs between December and March in Australia and in August in China.[2][3][4][5]

Apostasia wallichii was first formally described in 1830 by Robert Brown. Brown's manuscript was published in Nathaniel Wallich's book, Plantae Asiaticae Rariores.[6][7] The specific epithet (wallichii) honours Nathaniel Wallich.[7]

The yellow grass orchid grows in tropical forest and rainforest, sometimes near streams at altitudes of up to 1,000 m (3,000 ft). It is found in Hainan, south-west Yunnan, Bangladesh, Cambodia, India, Indonesia, southern Japan, Nepal, Malaysia, Myanmar, Sri Lanka, Thailand, Vietnam, the Philippines, New Guinea and Queensland where if occurs between Bamaga and Ingham.[2][3][5]