Pterostylis porrecta

Detailed description

Terrestrial tuberous herb growing in diffuse colonies. Sterile plants 20–50 mm tall, 3–4-leaved; leaves linear to linear-lanceolate, 40–70 × 4–6 mm, dark green, margins entire, apex acute to acuminate. Flowering plants 60–200 mm tall. Leaves 4–5, cauline, obliquely erect to spreading, sometimes arcuate; lamina linear-lanceolate, 45–120 × 4–6 mm, sessile, sheathing at the base; margins entire; apex acute to acuminate. Pedicel 10 mm long, slender. Ovary narrowly ellipsoid, 7–10 mm long, yellow-green, ribbed. Flower solitary, 18–22 mm long, semi-nodding, translucent white and pale green, darker towards the tip of the galea, the points of the sepals pale pink; galea shallowly gibbous at the base then leaning forwards before decurving in a shallow curve to the apex, the dorsal sepal much longer than the petals. Dorsal sepal ovate-lanceolate in outline when flattened, 19–22 × 9–11 mm, prominently expanded in the proximal third then gradually tapered to the acuminate apex. Lateral sepals obliquely erect top nearly horizontal, held well away from the galea, leaving a very wide lateral gap to the marginal petals; most of the labellum visible from the side through this gap; upper part of sinus flat when viewed from the side, sloping to a broad v when viewed from the front; internally the sinus projecting inwards as a small platform-like structure; conjoined part 7–9 × 5–6 mm wide at the top, narrowed to 1.6 mm wide at the base, the margins inrolled towards the apex and tapered into the free points, the free points 13–15 mm long, narrowly tapered to an attenuate apex, curved forwards, the tips often shallowly curved. Petals oblong-lanceolate, 16–19 × 3.0–3.5 mm, nearly straight, acute to acuminate, green with a white central area and two or three green stripes; flange vestigial. Labellum obliquely erect, shallowly curved forwards distally, the apex not protruding through the sinus in the set position; labellum hinge ligulate, 3 × 1 mm; lamina oblong, 8.0–9.0 × 2.3–2.5 mm, green to brownish green with a darker green central callus, apex obtuse, pinkish; callus 0.5 mm wide near the apex, raised; basal appendage 2.6–3.0 mm long, decurved. apex penicillate. Column 10–12 mm long, bent away from the ovary at about 50 degrees at the base then obliquely erect, green and white;column foot 3 mm long. Column-wings 4.5–5.0 mm long; basal lobe 2.0 × 0.7 mm, at an angle of 40 degrees, apex broadly obtuse, inner margins incurved, sparsely ciliate; mid-section 1.5 mm long, green; apical lobe 0.8 mm long, obtuse. Anther 1 mm long, shortly rostrate. Pollinia linear-clavate, 1.0–1.2 mm long, yellow, mealy. Stigma narrowly scutiform, 5.0–5.5 × 1.0–1.4 mm, situated just below column-wings raised. Capsule subcylindrical to broadly ellipsoid, 8–14 × 4–6 mm, initially yellow-green maturing grey.