Pterostylis paludosa

Detailed description

Terrestrial tuberous herb growing in dense colonies. Sterile plants 40–80 mm tall, 2–4-leaved; leaves linear-lanceolate, 25–60 × 7-11 mm, pale green to yellow-green (rarely dark green), margins entire or finely denticulate, apex subacute. Flowering plants 80–900 mm tall. Leaves 3–4, cauline, obliquely erect, pale green to yellowish green; lamina linear-lanceolate, 50–80 × 7–11 mm wide, sessile, sheathing at the base; margins entire or rarely finely denticulate; apex subacute. Pedicel 20–30 mm long, slender. Ovary 9–17 mm long, asymmetric, ribbed. Flower solitary, 18–20 × 5–6 mm, erect, translucent white and pale green to yellow green; galea gibbous at the base then erect before curving forwards in a shallow curve to the apex, the dorsal sepal slightly longer than the petals. Dorsal sepal ovate-lanceolate in outline when flattened, 24–26 × 13–16 mm, prominently expanded in the proximal third then suddenly narrowed and gradually tapered to the acute apex. Lateral sepals erect, tightly embracing the galea, with no lateral gap; upper part of the sinus very shallowly curved when viewed from the side, sloping to a narrow v when viewed from the front, scabrous; conjoined part 9–11 × 6–9 mm wide at the top, narrowed to 4 mm wide at the base, tapered into the free points; free points 9–11 mm long, tapered, erect, the tips extending just above galea. Petals obliquely oblong-lanceolate, 14–20 × 305 mm, falcate, acute, green with a white central area; flange vestigial. Labellum erect, curved suddenly forwards near the apex, raised; basal appendage 2.5–3.0 mm long, decurved, apex penicillate. Column 11.0–13.5 mm long, erect, green and white; column foot 1.5 mm long; wings 5.5–7.0 mm long; basal lobe 3.0 × 0.8 mm, at an angle of about 40 degrees, apex obtuse, inner margins incurved, sparsely ciliate; mid-section 2.5 mm long; green; apical lobe linear 1.2 mm long, obtuse. Stigma cordate, 3.0–3.3 × 2.0–2.2 mm, situated just below the column wings, raised. Anther 1.4 mm long, obtuse. Pollinia linear, 2 mm long, yellow, mealy. Capsules narrowly ellipsoid 15–17 × 3.0–3.5 mm, initially yellow green, maturing grey.