Pterostylis aquilonia

Pterostylis aquilonia is a terrestrial, perennial, deciduous, herb with an underground tuber and when not flowering, a rosette of light green leaves 5–15 mm (0.2–0.6 in) long and 5–12 mm (0.2–0.5 in) wide. Flowering plants have a single flower 20–25 mm (0.8–1 in) long and 10–12 mm (0.4–0.5 in) wide borne on a spike 150–200 mm (6–8 in) high. The flowers are white, green and reddish-brown. The dorsal sepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal curves forward and ends with a short point. The lateral sepals are erect with thread-like ends 22–25 mm (0.9–1 in) long with their tips bent forwards. The lateral sepals are held closely against the galea and there is a broad, flat, platform-like sinus between their bases. The labellum is 11–13 mm (0.4–0.5 in) long, about 2 mm (0.08 in) wide and brown and slightly protrudes above the sinus. Flowering occurs from May to June.[3]

Pterostylis aquilonia was first formally described in 1997 by David Jones and Bruce Gray. The description was published in The Orchadian from a specimen collected near Herberton.[1] The specific epithet (aquilonia) is a Latin word meaning "north" or "northern".[4]

The northern cobra greenhood grows in forest on the higher parts of the Atherton Tableland.[3]