About Pterostylis venosa Colenso
Pterostylis venosa Colenso is a terrestrial, perennial, deciduous herb that grows from an underground tuber, and it typically forms colonies of three or more individual plants. It produces a loose rosette of 2 to 4 leaves at its base, which are erect to spreading. In flowering individuals, these leaves reach approximately the same height as the flowering stem. The leaves are broadly oval, measuring 30–60 mm (1–2 in) long and 10–25 mm (0.4–1 in) wide. Flowering plants bear a single yellowish-green to dark green flower with white stripes, carried on a flowering stem 50–100 mm (2–4 in) tall. The dorsal sepal and petals are fused together to form a hood, called a "galea", that covers the column. The dorsal sepal is roughly erect near its base, then curves forward to a horizontal position, and the petals are approximately the same length as the dorsal sepal. A wide gap sits between the lateral sepals and the galea; the lateral sepals are erect, spread slightly apart from one another, and do not grow any higher than the galea. A broad V-shaped sinus is present between the lateral sepals. The labellum has a furry upper surface, is curved, and protrudes above the sinus. Flowering takes place between October and February. This greenhood orchid mostly grows in montane ecosystems, typically in Nothofagus forest, and often occurs in deep leaf litter or moss beds. It is found on the North, South and Stewart Islands.
