hood-shaped, arched over the lip. Lateral sepals and petals small, linear-subulate, seldom more than ½ as long as the lip. Lip large, involute, the margins meeting behind the column and enclosing it, orbicular-cordate when spread out; base with a rounded auricle on each side; apex truncate, entire or very slightly denticulate; disc with a thickened patch covered with deflexed hairs. Column short, stout, curved, swollen in front at the base.
North Island: Auckland—Kaitaia (Mongonui County), R. H. Matthews! July–August.
Clearly allied to C. oblonga, but the flower is larger, the lateral sepals and petals much reduced in size, the upper sepal narrower at the base and more hood-shaped at the top, and the margin of the lip is not coarsely fringed.
3. C. oblonga, Hook. f. Handb. N.Z. Fl. 266.—Variable in size, ½–2 in. high. Leaf sessile, ¾–1½ in. long, ovate-oblong, apiculate, rounded or cordate at the base, thin and membranous, conspicuously veined when dry. Flowers small, shortly peduncled, solitary or very rarely two together, about ¼ in. long, reddish-purple; bract rather large, sometimes foliaceous, erect. Upper sepal narrow, concave, oblong when spread out, obtuse or apiculate, arched over the lip. Lateral sepals and petals filiform, ¼–¾ in. long. Lip involute, the margins meeting behind the column and enclosing it, broadly semicordate when spread out; base with a rounded auricle or orifice on each side; apex truncate, coarsely toothed or fimbriate, centre of disc with minute dentiform papillæ. Column short, stout, curved to the front, with a swelling at the base.—Nematoceras oblonga, Hook. f. Fl. Nov. Zel. i. 250, t. 57b.
North and South Islands, Stewart Island: Not uncommon on moist shaded banks from the North Cape southwards. Sea-level to 2000 ft. September–November.
4. C. rivularis, Hook. f. Handb. N.Z. Fl. 266.—Very delicate and membranous, 1–2½ in. high. Leaf sessile, ½–2 in. long, ovate or oblong-ovate, acuminate, deeply cordate or almost 2-lobed at the base, very thin and membranous, veins conspicuous, reticulated. Flower shortly pedunculate or sessile between the lobes of the leaf, ⅓–½ in. long; bract narrow, acuminate. Upper sepal narrow, concave, arched over the lip, gradually tapering into a long filiform point. Lateral sepals and petals filiform, 1–2 in. long, the petals usually exceeding the sepals. Lip involute, the margins meeting behind the column and enclosing it, broadly ovate-cordate when spread out; base with a rounded auricle or orifice on each side; upper portion curved forwards and downwards, acuminate or apiculate, margins undulate, entire. Column very short, stout, erect.—Nematoceras rivularis, Hook. f. Fl. Nov. Zel. i. 251.
North and South Islands, Stewart Island: In damp wooded ravines from the North Cape southwards, but often local. Sea-level to 2000 ft. September–November.
