Pterostylis longipetala

Pterostylis longipetala is a terrestrial, perennial, deciduous, herb with an underground tuber and when not flowering, a rosette of between three and six egg-shaped, dark green leaves lying flat on the ground. Each leaf is 8–15 mm (0.3–0.6 in) long and 4–10 mm (0.2–0.4 in) wide. Flowering plants have a single flower 14–17 mm (0.6–0.7 in) long and 4–8 mm (0.2–0.3 in) wide which leans slightly forwards, on a flowering stem 100–160 mm (4–6 in) high with between three and five stem leaves. The flowers are dark green, brown and white. The dorsal sepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal has a thread-like tip 6–12 mm (0.2–0.5 in) long and the petals have pointed tips. The lateral sepals are erect, held closely against the galea, have thread-like tips 20–25 mm (0.8–1 in) long and a V-shaped sinus between their bases. The labellum is 12–15 mm (0.5–0.6 in) long, about 3 mm (0.1 in) wide, dark reddish-brown and curved, and protrudes above the sinus. Flowering occurs from April to June.[3][4][5]

Pterostylis longipetala was first formally described in 1943 by Herman Rupp from a specimen collected at Batemans Bay. The description was published in Proceedings of the Linnean Society of New South Wales.[1][6] The specific epithet (longipetala) is derived from the Latin words longus meaning "long"[7]^:494 and petalum meaning "petal".[7]^:616 Rupp did not give a reason for this epithet but did note that "the petals are narrower and longer than in any other species of Pterostylis known to me".[6]

The curved greenhood grows on moist slopes in coastal and near coastal forests in New South Wales.[3][4]