Citation: Rupp, Proc. Linn. Soc. N.S.W. 53:551 (1928).

Synonymy: Corysanthes diemenica Lindley, Gen. & Sp. Orch. Pl. 393 (1840); Corysanthes dilatata Rupp & Nicholls, Proc. Linn. Soc. N.S.W. 53:87 (1928); Corybas dilatatus (Rupp & Nicholls) Rupp, Proc. Linn. Soc. N.S.W. 53:551 (1928); Corysanthes fimbriata sensu R. Rogers in J. Black, Fl. S. Aust. 129 (1922), non R. Br. , Corysanthes pruinosa

Common name: Veined helmet-orchid.

Description:
Plant attaining a height of 1.5-4 cm; leaf orbicular-cotdate, apiculate, with a tendency to become 3-lobed, frosty on the undersurface, usually 1.5-3 cm long, with a circular marginal vein.

flower large, 18-20 mm long excluding the ovary, reddish-purple; ovary terete, 5-6 mm long; dorsal sepal at first erect, then incurved, c. 18 mm long, gradually contracted into rather a long claw, its lamina very blunt, broad and concave, almost horizontal, forming a hood projecting over and beyond the labellum; lateral sepals colourless, linear, acuminate, c. 4 mm long, connate at their bases with each other and also with the petals, directed more or less horizontally forwards; petals wider and shorter; narrowly falcate-subulate, c. 2 mm long, colourless, frequently 2-dentate, assuming variable positions but chiefly directed forwards; labellum large, crimson, sessile, its lower half vertical against the dorsal sepal, enclosing the column in a split tube of gradually increasing diameter; upper part acutely recurved, expanded into a trumpet-shaped orifice with more or less denticulate margins and directed forwards; lamina with a large convex smooth white boss in the centre of the reflexed part and a band of short reddish hairs or calli in front of the boss, the remaining surface quite smooth, at the base the tube dilated at each side of its attachment into a wide auricle, the orifices of which open downwards; column short, not winged, with a prominent wide fleshy shield-like base; pollinia attached without a caudicle to a large viscid disk of the rostellum; stigma reniform.

Published illustration: Pocock (1972) Ground orchids of Australia, pl. 52 as C. dilatatus; Woolcock (1984) Australian terrestrial orchids, pl. 27A.

Distribution:  Forms large colonies in shaded gullies or under bracken in forest or coastal heathland, often colonising pine plantations. S.Aust.: NL, MU, SL, KI, SE.   ?W.Aust.; N.S.W.; Vic.; Tas. Conservation status: native Flowering time: June — Aug.

SA Distribution Map based on current data relating to specimens held in the State Herbarium of South Australia

Biology: No text

Author: Not yet available