Diuris secundiflora

Diuris secundiflora, commonly known as the one-sided donkey orchid, is a poorly-known species of orchid that is endemic to New South Wales. It has a single grass-like leaf and up to eight yellow flowers that are sometimes spotted and are all arranged on one side of the flowering stem.

Description
Diuris secundiflora is a tuberous, perennial herb with a single leaf about 90 mm long, 3 mm wide and folded lengthwise. Between two and eight yellow flowers about 15 mm wide are borne on one side of a flowering stem about 500 mm tall. The dorsal sepal curves backwards, 8-10 mm long, about 6 mm wide and egg-shaped to spatula-shaped. The lateral sepals are linear, 30-40 mm long, about 1.5 mm wide and turned downwards. The petals spread widely or are more or less erect, egg-shaped, 6-7 mm long and about 5 mm wide on a dark reddish brown stalk 8-9 mm long. The labellum is about 6 mm long and has three lobes. The centre lobe is fan-shaped, 4 mm long and 6 mm wide with a central ridge. The side lobes are about 2 mm long and less than 1 mm wide. There are two thick callus ridges 2-3 mm long near the mid-line of the labellum. Flowering occurs in October and November.

Taxonomy and naming
Diuris secundiflora was first formally described in 1878 by Robert FitzGerald and the description was published in his book Australian Orchids.

Distribution
The one-sided donkey orchid is only known from the type location near the Macleay River "growing in a small cluster on an open bank".