Pterostylis calceolus M.A.Clem. APNI*
Synonyms: Oligochaetochilus calceolus (M.A.Clem.) Szlach. APNI*
Description: Terrestrial herb.
Rosette leaves 4–6, ovate to elliptic, 1.5–3 cm long, 8–12 mm wide, margins entire.
Scape to 20 cm high, with 2–4 closely sheathing stem leaves. Flowers 2–7, c. 1.2 cm long, semi-erect, transparent with green and red-brown markings and suffusions. Dorsal sepal with a decurved filiform point 4–5 mm long. Lateral sepals ovate in outline when flattened, conjoined part strongly concave, 6–7 mm long, 5–6 mm wide, margins incurved, glabrous; free points filamentous, 5–7 mm long, hooked forwards, c. 6 mm apart at the tips. Petals with well-developed proximal flanges that meet and block off the base of the galea. Labellum ovate to nearly sagittate, 4.5–5 mm long, c. 2 mm wide, reddish brown; marginal trichomes 4–6 pairs, 2–2.5 mm long, white, spreading; basal lobe hardly raised, with 8–10 pairs of white trichomes c. 1.5 mm long.
Distribution and occurrence: Grows in dry sclerophyll forest and woodland over shale or limestone; chiefly in the Bungonia district.
NSW subdivisions: ST
Pterostylis calceolus is very similar to P. hamata, differing only by its smaller uniformly red-brown flowers which are to 1.2 cm long and have a broader red-brown labellum. In contrast, the flowers of P. hamata are c. 2 cm long and with contrasting white and red-brown markings, and the labellum is brown.
Text by D.L. Jones, updated by Matt A.M. Renner (17 Dec 2019)
Taxon concept: Flora of NSW 4 (1993)
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