A very remarkable and distinct species, easily recognised by the thin acuminate leaf, very long filiform petals and lateral sepals, by the filiform point to the upper sepal, and acuminate lip.
5. C. rotundifolia, Hook. f. Handb. N.Z. Fl. 266.—Variable in size, ½–2 in. high. Leaf sessile or shortly petiolate, ½–1¼ in. long, broadly oblong or orbicular, tip rounded and apiculate, deeply cordate or 2-lobed at the base, rather fleshy, membranous when dry, veins reticulated. Peduncle at first very short, but elongating as the flower withers. Flower ½ in. long, dull-purple or purplish-green; bract short. Upper sepal narrow, concave, arched over the lip, acuminate. Lateral sepals and petals filiform, 1–1½ in. long. Lip tubular below, the margins meeting behind the column and enclosing it, base with a rounded auricle on each side; upper part abruptly recurved and expanded, tip acute, margins very minutely denticulate. Column short, stout, bent backwards.—C. orbiculata, Col. in Trans. N.Z. Inst. xxiii. (1891) 389. Nematoceras rotundifolia, Hook. f. Fl. Nov. Zel. i. 251.
North and South Islands, Stewart Island, Auckland and Campbell Islands: Moist wooded ravines throughout, but often local. Sea-level to 2500 ft. September–December.
This may not be the C. rotundifolia of the Handbook, which is described as having a truncate lip. It differs from C. rivularis in the more coriaceous leaf, with a rounded tip, in the upper sepal not being produced into a filiform point, and in the broader reflexed portion of the lip. From small forms of C. macrantha it is best distinguished by the almost sessile leaf and much smaller lip with an acute or acuminate tip. Mr. R. H. Matthews sends me specimens from Kaitaia with the leaves deeply lobed on each side, so as to be almost panduriform.
6. C. triloba, Hook. f. Handb. N.Z. Fl. 265.—Rather stout, variable in size. Leaf on a petiole ½–2 in. long; blade ½–1½ in. diam., reniform or orbicular, more or less distinctly 3-lobed at the tip, middle lobe acute, cordate at the base, fleshy when fresh, membranous when dry. Peduncle at first short, but elongating as the flower withers, and in fruit often 4–8 in. long. Flower ⅓–½ in. long, dull-purple; bract rather small. Upper sepal narrow at the base, dilated above, obovate-spathulate when spread out, arched over the lip, concave, obtuse at the tip. Lateral sepals and petals filiform, erect, ¾–2 in. long. Lip involute, tubular below, the margins meeting behind the column and enclosing it, and with a rounded auricle or orifice at the base on each side; upper part abruptly reflexed and much expanded laterally and downwards, forming a broad saucer-like entrance to the flower; margins erose or nearly entire. Column short, stout, bent backwards.—C. hypogæa, Col. in Trans. N.Z. Inst. xvi. (1884) 336. Nematoceras triloba, Hook. f. Fl. Nov. Zel. i. 250.
North and South Islands, Stewart Island: Shaded places from the North Cape southwards, but often local. Sea-level to 2000 ft. July–September.
