About Acianthus caudatus R.Br.
Acianthus caudatus R.Br. is a terrestrial, perennial, deciduous, sympodial herb, commonly known as mayfly orchid. It produces a single thin, egg-shaped to heart-shaped leaf, which is dark green on the upper surface and reddish-purple on the lower surface. The leaf measures 8–30 mm long and 6–20 mm wide, and has wavy or minutely toothed edges. Up to nine dark purplish flowers grow on a raceme that is 50–250 mm high; each individual flower is 30–40 mm long. The dorsal sepal is erect, expanded near its base, 15–25 mm long, and tapers to a fine point. The lateral sepals have a similar shape but are shorter, measuring 15–25 mm long, and spread apart from each other. The petals are narrow lance-shaped, 3–5 mm long, curved, and also spread apart from each other. The labellum is egg-shaped to wedge-shaped, 5–6 mm long and about 3 mm wide, with its tip pointing downwards. Flowering occurs from August to October. This species grows among low shrubs in open forest. It is distributed from south of the Manning River in New South Wales, through Victoria to the Eyre Peninsula in South Australia, and is also found in Tasmania.
