Pterostylis striata

Pterostylis striata, commonly known as the mainland striped greenhood, is a species of orchid endemic to south-eastern mainland Australia. As with similar orchids, the flowering plants differ from those which are not flowering. The non-flowering plants have a rosette of leaves but the flowering plants have a single flower with leaves on the flowering spike. This greenhood has a white flower with prominent dark green stripes and a brown-tipped dorsal sepal with a thread-like tip. Mainland striped greenhoods were formerly described as Pterostylis alata but that species is now recognised as a Tasmanian endemic.

Description
Pterostylis striata is a terrestrial, perennial, deciduous, herb with an underground tuber and when not flowering, a rosette of between five and nine dark green, wrinkled leaves, 4-15 mm long and 3-9 mm wide. Flowering plants have a single flower 16-19 mm long and 7-9 mm wide borne on a spike 40-250 mm high with three to five spreading stem leaves. The flowers are white with dark green stripes and a brownish tip. The dorsal sepal and petals are fused, forming a hood or "galea" over the column. The dorsal sepal curves forward with a thread-like tip 2-4 mm long. The lateral sepals are held closely against the galea and have erect, thread-like tips 14-20 mm long and a flat sinus with a small groove between their bases. The labellum is 7-9 mm long, about 3 mm wide, straight and just visible above the sinus. Flowering occurs from May to August.

Taxonomy and naming
Pterostylis striata was first formally described in 1877 by Robert FitzGerald from a specimen found near Yass. Fitzgerald published the description in his book Australian Orchids. Plants in this species were formerly described as Pterostylis alata but that species is now recognised as a Tasmanian endemic. The State Herbarium of South Australia still lists Pterostylis alata as occurring in that state.

Distribution and habitat
The mainland striped greenhood grows in a range of habitats from tea-tree scrub to forest and is widespread in Victoria. In New South Wales it is found south from Orange.