Pterostylis rubiginosa (D.L.Jones & L.M.Copel.) L.M.Copel. & D.L.Jones APNI* Synonyms: Speculantha rubiginosa D.L.Jones & L.M.Copel. APNI*
Description: Glabrous, tuberous, terrestrial herb.
Rosette leaves spreading, 2–7 per rosette; lamina ovate, 5–10 mm long, 4–8 mm wide, dull green; margins entire and plane or irregularly undulate; apex acute to acuminate; petioles 2–6 mm long, slender. Rosettes absent at anthesis.
Scape slender, wiry, 1–7-flowered. Sterile bracts sheathing, 2–5, oblong-obovate, 6–13 mm long, 3–5 mm wide, acute to acuminate. Fertile bracts closely sheathing, ovate-elliptical, 3–8 mm long, 3–4 mm wide, acute. Pedicels 1–3 mm long, slender. Ovaries narrowly ellipsoid, 3–5 mm long, smooth or slightly verrucose. Flowers well spaced, 1–3 open at once, angular, 8–9 mm long, 2.5–3 mm wide, rusty brown and white at the base, reddish brown towards the apex, sometimes wholly reddish and white, with shortly scabrous tips on the dorsal sepal, free points of the lateral sepals and petals; galea slightly inflated at the base, erect before curving forwards in an elongated semi-circle; petals longer than the dorsal sepal. Dorsal sepal ovate-lanceolate when flattened, 11–13 mm long, 4–6 mm wide, inflated at the base then tapered to the apex, boldly striped, scabrous, acute to subacute. Lateral sepals erect, closely embracing the galea; sinus curved inwards, the area below sloping gently to the ovary when viewed from the side, flat when viewed from the front with a central notch; frontal opening c. 2 mm wide; conjoined part 6–7 mm long, 4–5 mm wide, narrowed to c. 1.5 mm across at the base; free points erect or curved forwards, 2–2.5 mm long, tapered, acuminate, not reaching to the top of the galea. Petals oblong, 8–9 mm long, c. 2.5 mm wide, falcate, red brown with white stripes, darker towards the apex; flange c. 1 mm across, broadly deltate, obtuse. Labellum erect, not visible through the sinus in any position, nearly straight or curved forwards near the apex, red to red- brown and white. Labellum lamina narrowly oblong-elliptical, 3–3.5 mm long, 1–1.3 mm wide, obtuse; basal appendage decurved, c. 0.8 mm long, broadest at the base; apex trifid, erect. Callus a raised central red to red-brown ridge c. 0.3 mm across. Column 5–6 mm long, curved away from the ovary at 60° at the base then erect, red brown. Column wings c. 1.4 mm long; basal lobe broadly deltate, c. 0.6 mm long, c. 0.5 mm wide, red brown, at an angle of 50°; apex broadly obtuse; inner margins adorned sparsely with short, white cilia; mid-section c. 0.5 mm long, brown; apical lobe obliquely erect, filiform, c. 0.8 mm long, curved. Anther c. 1 mm long, obtuse. Pollinia linear, c. 1.1 mm long, yellow, mealy. Stigma situated towards the column base, broadly scutiform, c. 1.5 mm long, c. 1.3 mm wide, raised.
Flowering: Mid November to early December
Distribution and occurrence:
NSW subdivisions: NT
As at 18 August 2025 the relationships between Pterostylis rubiginosa and allied species are under investigation. Preliminary population genetic data suggest a very close relationship between P. rubiginosa and P. amabilis.
Text by Renner (18 August 2025)
Taxon concept: Jones DL, Copeland LM (2016) Four new species of Orchidaceae from the New England Tablelands of New South Wales. Australian Orchid Review 81(3): 40-48.
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.
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