Manual of the New Zealand Flora.
4. Caltha, Linn
4. Caltha, Linn.
Glabrous tufted perennial herbs; rootstock creeping. Leaves all or chiefly radical, oblong, ovate or rounded, cordate at the base or 2-lobed with the lobes turned upwards. Scape 1- or few-flowered. Sepals 5 or more, petaloid, usually deciduous. Petals wanting. Stamens numerous. Carpels several, sessile; ovules several or many, attached in 2 series to the ventral suture. Follicles 6 or more in a head, spreading, several-or many-seeded, opening along the inner face.
A small genus of 8–10 species, found in the temperate regions of both hemispheres. The southern species belong to the section Psychrophila, distinguished by the turned-up basal lobes or auricles of the leaves. Both the New Zealand species are endemic, although closely allied to the Australian and Tasmanian C. introloba.
Leaves entire or sinuate. Flowers yellow. Sepals linear-subulate, tapering from the base into almost caudate points 1. C. novæ-zealandiæ. Leaves dentate. Flowers white. Sepals oblong, obtuse or subacute, broadest above the middle 2. C. obtusa.
1. | C. novæ-zealandiæ, Hook. f. Fl. Nov. Zel. i. 12, t. 6.—A perfectly glabrous perennial herb 1–6 in. high. Rootstock stout, with fleshy rootlets. Leaves all radical, spreading; petiole variable in length, ½–4 in., grooved, base dilated, membranous, sheathing the stem; lamina ⅓–1 in. long, ovate-oblong, entire or sinuate, notched at the apex, deeply 2-lobed at the base, the lobes (auricles) turned upwards and almost appressed to the surface of the leaf. Scape solitary, naked, 1-flowered, ½–5 in. long, short at first but lengthening as the fruit ripens. Flowers pale-yellow, sweet-scented, ½–1 in. diam. Sepals 5–7, narrow, linear-subulate, tapering from the base into an almost caudate point, 3-nerved. Stamens 15–20. Carpels 6–12, ovate, narrowed into a short stout style. Follicles spreading, with a short hooked style; seeds few, 2–5.— Hook. f. Handb. N.Z. Fl. 9; Kirk, Students' Fl. 21. C. marginata, Col. in Trans. N.Z. Inst. xxiii. (1891) 382. North Island: Ruahine Mountains, Colenso! Tararua Mountains, Buchanan, Townson! South Island: Not uncommon on the higher mountains as far south as Stewart Island. Altitudinal range 2500 to 5500 ft. October–January. |
2. | C. obtusa, Cheesem. in Trans. N.Z. Inst. xxxiii. (1901) 312. —Smaller than C. novæ-zealandiæ, seldom more than 2 in. high. Leaves smaller; blade broader, wide-ovate or almost rounded, coarsely dentate, notched at the apex, 2-lobed at the base, lobes turned upwards and appressed to the surface, toothed. Flowers white, ½ in. diam., at first sessile among the uppermost leaves, but the scape elongates in fruit. Sepals 5, oblong. obtuse or subacute, broadest above the middle. Stamens 10–15. Carpels 5–8, narrow-ovate; style long, slender. Ripe fruit not seen. North Island: Herb. Colenso! (probably from the Ruahine Range, but without locality or collector's name). South Island: Mountains at the head of the Broken River, Canterbury, 5000–6000 ft., T. F. C. Otago—Mount St. Bathan's and Dunstan Mountains, 5000–6000 ft., Petrie! Black Peak, 6000 ft., Buchanan! The white flowers and blunt oblong sepals distinguish this at once from C. novæ-zealandiæ, but in a flowerless state it is easily mistaken for a dwarf form of that plant, although the leaves are always broader and coarsely dentate. The sepals are markedly different from the long tapering almost caudate sepals of C. novæ-zealandiæ. I have not been able to compare it with the Australian and Tasmanian C. introloba, F. Muell., which is said to have white flowers, but judging from descriptions it can hardly be the same. |