About Pterostylis sargentii C.R.P.Andrews
Pterostylis sargentii is a terrestrial, perennial, deciduous herb that grows from an underground tuber. Non-flowering individuals produce a rosette of three to six leaves on a short stalk; these leaves measure 5–18 mm long and 3–8 mm wide. Flowering plants do not have a rosette, instead bearing three to ten stem leaves along the flowering stem. These stem leaves are 8–30 mm long and 2–4 mm wide, and the entire flowering stem grows to 50–200 mm in height. Up to six striped flowers, colored white with green or brown stripes, develop on the flowering stem. Individual flowers are 15–25 mm long and 5–7 mm wide. The dorsal sepal and petals form a hood called a "galea" that covers the column, and the dorsal sepal has a thread-like tip 2–3 mm long. The lateral sepals are turned downwards, joined for roughly half their length, then narrow suddenly to fine tips that are 4–6 mm long. The labellum is 4–5 mm long and about 2 mm wide, dark brown, and divided into three lobes; the two side lobes each have a large, horn-like appendage. Flowering takes place from July to October. This species, commonly known as frog greenhood, occurs in a wide variety of habitats across the south-west of Western Australia, and is especially common between Mullewa and Grass Patch.
