Common name: Small Bearded Greenhood
Pterostylis tasmanica D.L.Jones APNI*
Synonyms: Plumatichilos tasmanicum (D.L.Jones) Szlach. APNI*
Description: Terrestrial herb
Leaves 8–14, lanceolate to elliptic, 1.0–2.4 cm long by 3–7 mm wide, dark green, some with a few pale variegations, the lower leaves petiolate, arranged in a tight rosette, distal leaves sessile and closely embracing the stem, apex acuminate; petioles 1–8 mm long by 1.0–1.5 mm wide, narrowly winged.
Flower solitary or rarely two, 18–25 mm long, translucent green with darker green reticulate veins, brownish towards the apex of the galea and lateral sepals; galea erect in proximal two-thirds then obliquely erect or curved forwards nearly at right angles. Drrsal sepal 18–24 mm long by 12–13 mm wide, inflated at the base and tapered toward the apex, with a short apical point 0.5–1.5 mm long. Lateral sepals deflexed; conjoined part 7–9 mm long by 3–4 mm wide, narrowed to c. 2 mm across at the base, with with a thickened, dark green central pad, the margins incurved, free points 7–11 mm long, linear, thickened, usually brown, parallel or slightly divergent, apex subacute. Petals strongly asymmetric, falcate, 15–20 mm long by 1.5–2.0 mm wide, dark green, narrowed in the distal half to an attenuate, long-acuminate filament; flange c. 0.5 mm across, obscure. Labellum porrect, curved, filiform, densely beset with yellow trichomes 2–4 mm long, with a dark vinaceous apical knob c. 2 mm by 1.3 mm; laminar linear-filiform, 13–15 mm long by 0.5 mm wide, widened into a narrowly ovate slightly wrinkled base c. 1.5 mm across, then abruptly tapered into a short beak tapered slightly from the base to the apex; a series of short, pale, erect hairs present on the basal swelling.
Distribution and occurrence: Tasmania, Victoria, New South Wales and New Zealand. In New South Wales evidently known by a single gathering on the South Coast.
Beneath Allocasuarina on a coastal headland.
NSW subdivisions: SC
Other Australian states: Vic. Tas. S.A.
Pterostylis tasmanica can be distinguished from P. plumosa by its the galea apex bearing a short rostrum to 1.5 mm long, or no rostrum at all; and the dense yellow labellum trichomes. In P. plumosa the galea rostrum is c. 4 mm long and the labellum trichomes are sparse.
Text by Matt A.M. Renner (16 Dec 2019) based on Jones (1994).
Taxon concept: Jones DL (1994) Nine new species of Orchidaceae from south-eastern Australia. Muelleria 8: 177–192.
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
***The AVH map option provides a detailed interactive Australia wide distribution map drawn from collections held by all major Australian herbaria participating in the Australian Virtual Herbarium project.