About Pterostylis alpina R.S.Rogers
Pterostylis alpina R.S.Rogers is a terrestrial, perennial, deciduous herb that grows from an underground tuber. It produces a rosette of three to five leaves that surround the base of the flowering stem; each leaf is egg-shaped to elliptic, measuring 30 to 60 millimeters long and 15 to 30 millimeters wide. A single white flower with dark green markings, 25 to 30 millimeters long and 9 to 12 millimeters wide, is borne on a flowering spike that stands 120 to 300 millimeters high. The dorsal sepal and petals are fused together to form a hood, called a "galea", that covers the column. The dorsal sepal curves forward and ends in a pointed tip. A wide gap sits between the galea and the lateral sepals. The lateral sepals are swept backward, have thread-like tips that are 13 to 18 millimeters long, and have a bulging sinus between them. The labellum is 12 to 14 millimeters long, about 3 millimeters wide, colored dark green to brown, blunt-tipped, curved, and protrudes above the sinus. Flowering occurs from August to October. This species, commonly called the mountain greenhood, is widespread across northern and eastern Victoria, Australia, and is only found in the Batlow region of New South Wales. It grows in high-elevation forest habitats with high rainfall, often on south-facing slopes.
