Pterostylis subtilis

Pterostylis subtilis is a terrestrial, perennial, deciduous, herb with an underground tuber and a rosette of fleshy leaves lying flat on the ground. Each leaf is 30–50 mm (1–2 in) long and 15–25 mm (0.6–1 in) wide. When flowering, there is a single white flower with dark green lines, 35–45 mm (1–2 in) long and 15–20 mm (0.6–0.8 in) wide which is borne on a flowering spike 120–250 mm (5–10 in) high. The dorsal sepal and petals are fused to form a hood or "galea" over the column, the dorsal sepal slightly longer than the petals and all sharply pointed. There is a narrow gap at each side of the flower between the petals and lateral sepals. The lateral sepals are erect with a tapering tip 15–20 mm (0.6–0.8 in) long and there is a deep, narrow sinus between them. The labellum is 16–20 mm (0.6–0.8 in) long, about 3 mm (0.1 in) wide, blunt and curved, protruding above the sinus. Flowering occurs in December and January.^[2]

Pterostylis subtilis was first described in 2006 by David Jones and the description was published in Australian Orchid Research from a specimen collected in the Barrington Tops National Park.^[3] The specific epithet (subtilis) is a Latin word meaning "thin", "fine", "slender" or "acute ".^[4]

The thin mountain greenhood grows with grasses on sheltered forest slopes in the Barrington Tops National Park.^[2][5]