About Prasophyllum colensoi Hook.f.
Prasophyllum colensoi Hook.f. is a terrestrial, perennial, deciduous herb that grows from an underground tuber. It produces a single dark green, tube-shaped leaf that is 120–350 mm (5–10 in) long and 2–5 mm (0.08–0.2 in) wide, with a whitish base. The free, exposed portion of the leaf measures 80–120 mm (3–5 in) in length. Between five and twenty lightly scented flowers are crowded along a flowering spike 30–120 mm (1–5 in) long. The flowers are yellowish-green to reddish-brown and 10–11 mm (0.39–0.43 in) long. Like other species in the genus Prasophyllum, the flowers of this species are inverted, meaning the labellum sits above the column rather than below it. The dorsal sepal is roughly egg-shaped, 6–7 mm (0.2–0.3 in) long and about 2 mm (0.08 in) wide. The lateral sepals are linear to lance-shaped, around the same size as the dorsal sepal or slightly narrower, and grow almost parallel to one another. The petals are 6–7 mm (0.2–0.3 in) long, about 1.5 mm (0.06 in) wide, and curve downwards. The labellum is egg-shaped to lance-shaped, 6–7 mm (0.2–0.3 in) long and about 4 mm (0.2 in) wide, with its outer tip turned upwards so that the tip often extends between the two lateral sepals. A thick, fleshy callus grows in the center of the labellum. Flowering takes place from October to March. This leek orchid is widespread on both the North and South Islands of New Zealand, where it grows in grassland, among other herbs, and around the edges of bogs.
