Nematoceras macrantha
(the large flower)

The oblong-orbicular, apiculate leaf is carried on a long petiole which raises it above the flower. The petals are about half the length of the lateral sepals. Appears to hybridise with both triloba and rivularis s.l.

Distribution: endemic - North, South, Stewart, Chatham and Auckland Is.

Flowers: October-January - insect pollinated.

Nematoceras orbiculata
(the shape of flattened-out labellum - the species was described from dried and pressed material)

Labellum disc dark red, the margins inrolled to produce a narrow-acuminate appearance. Petals and lateral sepals conspicuously short, only slightly exceeding the dorsal sepal.

Distribution: endemic - North Id.: southwards from the Volcanic Plateau. South, Stewart and Chatham Is.

Flowers: July-October - insect pollinated.

Nematoceras papa
(the mud-stone on which the plant grows)

cf N.rivularis s.l. q.v.

Distribution: endemic - North Id.: northern Taranaki.

Flowers: September-October - insect pollinated.

Nematoceras rivularis
(pertaining to streams)

N. rivularis s.s., which now has a restricted distribution, forms large colonies in wet places, stream banks and cliff face seepages. The leaf is near orbicular, sessile, apiculate, with dark spots along the edge. The petals are usually as long as the lateral sepals, while the labellum is dark red.

The majority of plants found, while generally similar to the type, belong to an undescribed aggregate with numerous tag-named forms, some of which are sure to be valid species. They are referred to as rivularis s.l.

Distribution: endemic - rivularis s.s. North Id.: the Russell -KeriKeri district and about New Plymouth.
rivularis s.l. occurs throughout the North, South and Stewart Is.

Flowers: September-October - insect pollinated.

Nematoceras triloba
(the 3-lobed leaf)

Dorsal sepal ± obtuse, the petals barely half the length of the long, upright lateral sepals. A very variable plant, some forms of which are almost certainly valid species, others more likely to be hybrids.

Distribution: endemic - North, South, Stewart, Chatham, Auckland and Campbell Is.

Flowers: June-December, depending on altitude - insect pollinated.