Flora Australiensis 6 327 (1873) APNI
Flowering plant usually 25–60 cm tall, slender to moderately stout. Leaves 1–4, usually 2, linear, channelled, 5–30 cm long. Flowers 1–10, erect, mauve or purple, often with darker suffusions, sometimes fragrant; pedicel (excluding ovary) 2–5 cm long, mostly enclosed within bract; dorsal sepal erect, broadly ovate, 12–25 mm long; lateral sepals deflexed, usually parallel, narrow-linear, greatly exceeding petals, 30–60 mm long; petals obliquely erect, ovate to elliptic, tapering to base or distinctly clawed, 13–25 mm long. Labellum 3-lobed from base, 12–18 mm long; lateral lobes erect, about half as long as mid-lobe, oblong, margins entire; mid-lobe keeled, shortly clawed, broadly fan-shaped to wedge-shaped, margins irregular, with 2 longitudinal yellow ridges from the base ending in tooth-like processes around midway along lamina. Column narrowly winged. Flowers Oct.-Nov.
Also SA, Qld, NSW, ACT. Formerly widespread and common in Victoria, occurring in the open forests, woodlands and grasslands of the fertile lowlands, now much reduced through clearing for agriculture and restricted to relatively few, isolated sites, but sometimes locally abundant.
Although previously including up to seven subspecific taxa, only two varieties of Diuris punctata are currently accepted (although some entities formerly included in D. punctata have been raised to species level). D. punctata var. sulfurea, with yellow flowers, is restricted to northern New South Wales, and all Victorian specimens are referable to D. punctata var. punctata.
A later flowering taxon similar to Diuris punctata but with white and pale mauve flowers is known from Gippsland (see D. sp. aff. dendrobioides (Bairnsdale)).