Citation: Reichb. f., Beitr. Syst. Pfl. 70 (1871).

Synonymy: Disperis alata Labill., Nov. Holl. Pl. Sp. 2:59 (1806); P. praecox Lindley, Gen. & Sp. Orchid. Pl. 388 (1840) , Diplodium alatum

Common name: Striped green-hood.

Description:
Slender, 8-25 cm high, 3-8 ovate leaves in rosettes on long petioles on noB-flowering plants but basal leaves absent on flowering plants, stem leaves gradually increasing in size from below upwards, lanceolate, acuminate, stem clasping, the lower ones bract-like.

Flower single, pale-green or white with darker striations; galea erect, 20-25 mm long, gradually incurved, apex blunt; dorsal sepal ending in a fine point; petals blunt or acute; lateral sepals (lower lip) erect; the lobes separated by a narrow sinus with a notch in the middle, not bulging, the tips produced into long filiform points, embracing the galea and greatly exceeding it; labellum on a movable claw, lanceolate, c. 8 mm long, tapering to a more or less acute point, almost straight and slightly exceeding the column, greenish, central raised line not very distinct; basal appendages narrow-linear, much curved, penicillate; column erect, winged; tip of wings falcate, acute; lower lobe oblong, blunt with inturned ciliate margins; stigma prominent, 2-lobed, elliptic, centrally placed on the column.

Published illustration: Woolcock (1984) Australian terrestrial orchids, pl. 49C.

Distribution:  Forms small to extensive colonies in rocky or shady locations in forest or forest-heathland in areas receiving greater than 600 mm mean annual rainfall. S.Aust.: SL, KI, SE.   N.S.W.; Vic.; Tas. Conservation status: native Flowering time: May — July.

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

Biology: Plants from the SL and KI are much larger than those from the SE and more closely resemble Pterostylis robusta but where the two are sympatric they remain distinct, P. alata being a taller more slender plant with narrower flowers, rosettes of non-flowering plants being only half the size of P. robusta rosettes.

Author: Not yet available