Green Column Caladenia

C. chlorostyla is a terrestrial, perennial, deciduous, herb, usually occurring as a solitary individual. It has an underground tuber and a single sparsely hairy, bright green, narrow linear leaf up to 5–15 cm (2–6 in) long and 1–3 mm (0.04–0.1 in) wide. One, sometimes up to five, unscented flowers up to 11–16 mm (0.4–0.6 in) in diameter are borne on a thin, wiry spike, 1–30 cm (0.4–10 in) tall. The sepals and petals are white, pale mauve or pinkish with greenish-white tips. The dorsal sepal is erect with its sides turned forwards, the lateral sepals are held horizontally and flat and the petals either spread widely or turn inwards. The dorsal sepal is 6–11 mm (0.2–0.4 in) long and narrow egg-shaped, the lateral sepals and petals are 6–8 mm (0.2–0.3 in), about 2 mm (0.08 in) wide, curved like a sickle and egg-shaped with the narrower end towards the base. The column is green with transverse red bars. Flowering occurs between September and January and is followed from December to April by the fruit which is a green, oval-shaped capsule 10–12 mm (0.4–0.5 in) long which sometimes has purple stripes.

This caladenia grows in sunny position in scrub but also in old-growth forests and frequently in mature pine plantations. C. saccata is regarded as a synonym of C. chlorostyla in New Zealand.