Common Sun Orchid

Thelymitra longifolia is a tuberous, perennial herb with a single ribbed, linear to lance-shaped leaf 50–380 mm (2–10 in) long and 10–40 mm (0.4–2 in) wide. Up to five or more white or very pale pink flowers, reddish green on the back, 8–18 mm (0.3–0.7 in) wide are borne on a flowering stem sometimes up to 1,000 mm (40 in) tall. The three sepals and three petals (including the labellum) are alike except that the dorsal sepal in slightly wider. The column is white or brown near its base but dark brown to black near its tip. The lobe on the top of the anther is usually rounded and yellow and the side lobes have dense, tangled white hairs. Flowering occurs from September to February.

The white sun orchid usually grows in sunny places in open areas amongst scrub, but sometimes in dense forest. It is found on the North, South, Stewart, Three Kings, Chatham and Auckland Islands. It has also been reported from Norfolk Island but there is doubt that those collections match the type specimen.