About Diuris corymbosa Lindl.
Diuris corymbosa Lindl., commonly called the common donkey orchid, is a tuberous perennial herb. It typically grows to a height of 20 to 40 cm (8 to 20 in), with two or three leaves emerging from its base; these leaves measure 120 to 250 mm (5 to 10 in) long and 5 to 10 mm (0.2 to 0.4 in) wide.
It produces up to eight yellow flowers marked with purple and brown blotches. Each flower is 20 mm (0.8 in) long and 20 to 30 mm (0.8 to 1 in) wide. The flowers have long, wide petals that resemble donkey ears, a short, wide, erect dorsal sepal, and narrow hanging lateral sepals that are sometimes crossed. The labellum has three lobes: the lateral lobes are broad and spreading, while the middle lobe is short and shaped like an inverted V or flattened. Flowering occurs from September to October, and sometimes begins as early as August.
This species grows in woodland, often on swamp margins, and is found between Dongara and Albany.