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Manual of the New Zealand Flora.
20. Corysanthes, R. Br
20. Corysanthes, R. Br.
Dwarf very delicate succulent terrestrial herbs. Boot of small rounded tubers on fleshy caudicles. Leaf solitary, ovate-cordate or orbicular or reniform. Flower solitary, large for the size of the plant, at first almost sessile on the leaf, but peduncle elongating considerably in fruit. Upper sepal large, erect and incurved, helmet-shaped; lateral free, small and linear, or long and filiform. Petals similar to the lateral sepals but smaller, sometimes wanting. Lip large, the lower portion tubular, the margins meeting behind the column and enclosing it; base with a rounded auricle on each side of the column or with a hollow conical spur; upper part truncate or expanded into a broad abruptly reflexed limb; margins entire or denticulate or fimbriate. Column short, straight, 2-winged at the top; stigma broad, placed just under the rostellum. Anther large, terminal, erect, 2-celled; pollinia 4, powdery, free.
A very curious genius of about 16 species, found in Malaya, Australia, and New Zealand, the species of each country being endemic.
A. Lip produced downwards into 2 conical spurs at the base. Lateral sepals and petals minute.
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Leaf¼½ in., sessile, ovate-cordate 1. C. Gheesemanii. B. Lip with 2 rounded orifices at the base. Lateral sepals and petals filiform, longer than the lip (except in C. Matthewsii).
Leaf ½–1 in., sessile, ovate- or orbicular-cordate. Lateral sepals and petals about half as long as the lip. Lip truncate, entire or minutely denticulate 2. C. Matthewsii. Leaf ¾–1½ in., sessile, ovate-oblong, rounded or cordate at the base. Lip truncate, coarsely toothed or fimbriate 3. C. oblonga. Leaf ½–2 in., sessile, oblong-ovate, acuminate. Upper sepal acuminate. Lip bent forwards and downwards, acuminate. 4. C. rivularis. Leaf½–1¼ in., sessile or shortly petiolate, broadly oblong or orbicular, apiculate. Upper sepal acute. Lip ab- ruptly reflexed and expanded, apex acute 5. C. rotundifolia. Leaf ½–2 in., petiolate, orbicular or reniform, 3-lobed at the tip. Upper sepal obtuse. Lip abruptly reflexed and expanded, apex rounded 6. C. triloba. Large and stout, 2–8 in. high. Leaf on a petiole ½–3 in. long; lamina ½–3 in., broadly oblong or orbicular. Upper sepal acute. Lip large, abruptly reflexed and much expanded 7. C. macrantha.
| 1. | C. Cheesemanii, Hook. f. ex T. Kirk in Trans. N.Z. Inst. iii. (1871) 180.—A very small species, ½–1 in. high when in flower, rarely more. Leaf sessile, ¼–½ in. long, ovate-cordate or orbicular-cordate, apiculate, membranous, veins conspicuous when dry. Flower sessile or shortly peduncled, about ⅝ in. long, dull-purple; bract short, sheathing. Upper sepal very large, helmet-shaped, curved over the lip, obtuse. Lateral sepals minute, subulate, erect, placed between the basal spurs of the lip. Petals frequently wanting, when present very minute, deflexed, placed under or behind the basal spurs of the lip. Lip very large, tubular, the margins involute and meeting behind the column and enclosing it, the base produced downwards on each side into a short conical spur; the mouth expanded and abruptly recurved; margins entire. Column short, stout, erect, with a large fleshy gland at the base. Anther terminal, very large. Capsule ⅓ in. long, linear-oblong, elevated on the greatly elongated peduncle, which is sometimes over 6 in. long. —Ic. Plant, t. 1120.
North Island: Auckland—Kaitaia, R. H. Matthews! vicinity of Auckland, T. F. C. South Island: Near Westport, W. Townson! June–July. A very curious little plant, probably not uncommon, but easily overlooked, from its small size and early flowering-period. It is very closely allied to the Australian C. bicalcarata, and may prove identical with it. |
| 2. | C. Matthewsii, Cheesem. in Trails. N.Z. Inst. xxxi. (1899) 351.—Small, delicate, ¾–1½ in. high. Leaf sessile, ½–1 in. long, ovate-cordate or orbicular-cordate, acute or obtuse, membranous when dry, showing 1 or 2 circular veins on each side of the midrib connected by transverse veinlets. Flower shortly peduncled, about ⅓ in. long, horizontal or drooping, purplish-green; bract small, erect. Upper sepal very narrow at the base, broadened above and page 694hood-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 papillse. 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, 1–2½in. 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. page 695A 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 rotundi- folia, 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. Prom 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.—Bather 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. hypogsea, 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. page 696 |
| 7. | C. macrantha, Hook. f. Handb. N.Z. Fl. 266.—Much larger than the other species, 2–8 in. high or more. Leaf on a petiole ½–3 in. long; lamina ¾–2 in. diam., broadly oblong or orbicular, obtuse or apiculate 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. Peduncle from the base of the petiole, at first short, but elongating as the flower withers, often 4–10 in. long in fruit. Flower large, ½–1 in. long, dark-purple; bract small. Upper sepal narrow, concave, arched over the lip, somewhat expanded above, acute or acuminate. Lateral sepals and petals filiform, 1–2 in. long. Lip large, tubular below, the margins meeting behind the column and enclosing it, base with a rounded auricle on each side, upper part abruptly recurved and much expanded all round, margins undulate, minutely erose or denticulate. Column short, stout, bent backwards.—C. papillosa, Col. in Trans. N.Z. Inst. xvi. (1884) 337. Nematoceras macrantha, Hook. f. Fl. Nov. Zel. i. 229, t. 57A.
North and South Islands, Stewart Island, Chatham Islands, Auckland and Campbell Islands: Not uncommon in damp shaded places throughout. Sea-level to 2500 ft. October–December. Closely allied to C. triloba, but much larger, the leaves rarely 3-lobed at the tip, the upper sepal acute or acuminate, and the lip larger. Both it and G. triloba frequently have the peduncle bent backwards, so that the flower lies with the upper sepal undermost and the lip above. |