Pterostylis cardiostigma D.Cooper

Plant 6-35-(40) cm tall, from a large heart-shaped tuber with 4 or 5 lateral roots (Fig. 1). Internodes very short, stem thickish, lower portion covered by pink to red overlapping leaf sheaths with darker red stripes; 3-4 pink to red sheathing bracts at base. Leaves 5-7, cauline, sessile; often very upright especially in young plants (Fig. 2M,N); all except lowermost usually overtopping galea, lowermost 2 leaves are usually shorter, leaves 3rd and 4th from base usually largest; lamina 8-23 cm by 1-2 cm, linear-lanceolate, acuminate (Fig. 1); midrib red, slightly grooved above, 2(3) lateral yellow veins on either side, keel prominent, often red. Green flower solitary, erect, tall and narrow. Dorsal sepal to 7 cm long, vertical in lower half, upper half steeply inclined (Fig. 2D) or very occasionally more horizontal, tip acuminate, red. Lateral sepals diverging at a very narrow angle, with long filiform red caudae overtopping galea by 2 cm. Petals 5-10 mm shorter than dorsal sepal, long marginal strip exposed, tips red; galea width at petal tip 6 mm. Labellum (Fig. 2K,L) long triangular, arched in upper third, tip acuminate (Fig. 2H,I); distal half red with retrorse pale hairs on upper surface and a darker red dorsal median ridge becoming paler towards base; lower surface with red median groove (Fig. 2L). Column shorter than labellum (Fig. 2A), stigma heart-shaped, very prominent. Ovary erect, 1-3 cm high.

[Reproduced from Cooper (1983, New Zealand J. Bot. 21: 97–100) with permission from The Royal Society of New Zealand.]