Corybas macranthus (Hook. f.) Rchb. f.

Plant: Much larger than the other species, 5 – 20 cm or more  (up to 22)  

Stem: Short 

Leaf: on a petiole 1.3 -7.5 cm long; lamina 2 - 5 cm diam., broadly oblong or orbicular, obtuse or apiculate/mucronate or rarely 3-lobed at the tip, cordate or 2-lobed at the base, thick and fleshy when fresh, thin and membranous when dry, veins finely reticulate ; light green above, silver-backed, often with brownish purple markings on edge of upper surface

Peduncle: from the base of the petiole, at first short, but elongating as the flower withers, often 10-25 cm long in fruit 

Bract: very small 

Ovary: short, curved

Flower: large, 1.3 – 2.5 cm long, dark-purple; Irwin: labellum dark reddish black, the whole flower 1.5 cm across. The northern form has a tawny patch in the centre of the purple-brown labellum and a tawny dorsal sepal. It only grows in shade and always has the flower below the leaf. The southern form has an all-dark labellum and dorsal sepal. The flower is usually borne above the leaf in exposed sites.

Dorsal sepal: narrow, concave, arched over the lip, somewhat expanded above, acute or acuminate; horizontal, lanceolate, larger than lip; acuminate, usually longer than labellum, horizontal or recurved

Lateral sepals:  erect, filiform-caudate, 2.5-5 cm long 

Lateral petals: filiform, 2.5-5 cm long, shorter than sepals (1/3 of length?), often horizontal; occasionally with irregular fleshy lobes

Labellum: large, tubular below, the margins meeting behind the column and enclosing it, upper part abruptly recurved and much expanded all round, margins undulate, minutely erose or denticulate ; broader than long, 1.3 cm long; expanded roughly funnel-shaped, anterior margin irregularly crenulate, obtuse emarginate or apiculate 

Auricles: rounded  

Column: short, stout, erect or bent backwards. Wings exceeding the anther

Capsule: on peduncle elongating up to 20 cm 

Type: Hooker’s illustration under Nematoceras macrantha (FI. Nov. Zel., 1, 1853, 250, t. 57 a.) can be regarded as the hypotype of the species.

Distribution: North and South Islands, Stewart Island, Chatham Islands, Auckland Islands, Campbell Islands 

Ecology: Not uncommon in damp shaded places throughout. Insect-pollinated. ; well-lit sites, often under scrub, and forming large, loose colonies of many plants.

Elevation: Sea-level to 1500 m