Citation: M. Clements, sp. Nov.1

Synonymy: P. mitchellii sensu J. Weber & Bates in J. Black, Fl. S. Aust. 443 (1978), non Lindley. , Oligochaetochilus ovatus

Common name: Gawler Range green-hood.

Description:
Short but stout, 5-15 cm high; leaves 3-7, in a basal rosette which may be withered at flowering, shortly petiolate, lamina ovate-lanceolate, 1-3 cm long, glabrous, often glaucous; stem bracts 1-3, ovate-lanceolate, 2-3 cm long, acute, sheathing or clasping the stem, a further bract subtending each flower; pedicel slender, 5-15 mm long; ovary green with 3 brown ridges.

Flowers 1-6 in a crowded raceme, greenish-white with brown, red or pink striations; galea c. 3 cm long, at first erect then decurved, gibbous near the base, with transparent membranous wings up to 1 cm wide, apex shortly acuminate; lateral sepals (lower lip) recurved and reflexed, ovate to elliptic, lamina waxy, concave, produced into fine parallel acuminate points 1-2 cm long; the sinus narrow, the margins thickened, glabrous or with a few sparse cilia posteriorly; labellum attached by a long broad claw, ovate to elliptic, 4-6 mm long, membranous, lamina shallowly dished, red or pink with darker stripes and raised median longitudinal rib, apex obtuse, upturned, with a small beak-like projection below; posterior margin with a thickened, .basal appendage beset with a crest of setae c. 1 mm long, the lateral margins and tip beset with sparse setae also, the setae 1-2 mm long, fine, regular; undersurface smooth; column incurved, 14-20 mm long, with rectangular wings, the upper angle toothed and ciliate, the anterior margins with inturned cilia, lower lobe blunt; stigma ovate-lanceolate, with an acute brown angle, the margins raised.

Published illustration: A. Prescott (1984) Cover of the J. Nat. Orch. Soc. S. Aust. 1-11.

Distribution:  Occurs singly or in small populations on granite porphyry or quartzite outcrops in shallow red soils, in very open situations. Locally common. S.Aust.: GT, EP. Conservation status: native Flowering time: Sept. — Oct.

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

Biology: No text

Taxonomic notes: Pterostyis ovata M. Clements, sp. nov. Affinis Pterostylidi bisetae Blackmore & Clemesha, a qua habitu crasso; sepalis lateralibus brevibus, connatis, ovatis ad ellipticas, 2-3 cm longis apicibus acuminatis includentibus; petalis translucentibus; et labello oblongo paribus multis setarum brevium, differt. Holotype: Cultivated in Canberra ex "South Australia, Gawler Ranges, hills and S.E. edge of Lake Acraman", 17 Oct. 1977, M. A. Clements 2458 (CBG). Isotypes: AD, PERTH, K.

Author: Not yet available