About Acianthus sinclairii Hook.f.
Acianthus sinclairii Hook.f. is a terrestrial, perennial, deciduous, sympodial herb. It grows a single heart-shaped, glabrous, dark green leaf, which often has a maroon tinge or markings. This leaf measures 10–30 mm (0.4–1 in) long, and is positioned between one quarter and halfway up the plant's slender stem. At flowering time, the stem is about 100 mm (4 in) long, and it grows longer after flowering. Acianthus sinclairii produces up to ten flowers, each 6–8 mm (0.2–0.3 in) long. The flowers are green with purple blotches, and have a dull red labellum. The dorsal sepal is broadly lance-shaped to egg-shaped, and forms a hood that covers the column. The lateral sepals are about the same length as the dorsal sepal, but have pointed tips and face forward beneath the labellum. The petals are somewhat shorter than the sepals, are lance-shaped, and spread widely. The labellum is also shorter than the sepals; it is dished, broadly egg-shaped with edges turned under, dull red, and bears two rounded calli at its base. Flowering occurs between January and October. This orchid usually grows in shaded shrubland and forest, only rarely occurring in sunny habitats, but it often grows near streams or other moist areas. It is found on the North Island, South Island, Stewart Island, Chatham Island, and Raoul Island in the Kermadec Group.
