T. F. C. Otago—Maniototo Plains, Roxburgh, Petrie! E. W. Bastings! In muddy and watery places, often submerged. Altitudinal range from sea-level to 3000 ft. December–April.
A very peculiar little species, readily known by the narrow-linear spathulate leaves and minute tetramerous flowers. Sir J. D. Hooker has compared it with the Falkland Islands R. hydrophilus, and with R. Moseleyi from Kerguelen's Islands, so far as habit and leaves are concerned. In the flowers and fruit it differs largely from both.
37. R. parviflorus, Linn. Sp. Plant. 780; var. australis, Benth. Fl. Austral. i. 14.—A small slender hairy annual, with sparingly branched suberect or decumbent stems 2–5 in. long. Leaves small, radical and cauline, on slender petioles ¾–1½ in. long; blade thin and membranous, orbicular in outline, 3–5-toothed or -lobed, sometimes divided to the base. Flowers very minute, on the branches opposite the leaves, sessile or nearly so. Sepals fugacious. Petals 4–5. slightly longer than the sepals. Mature achenes 3–6, compressed, margins thin, sides covered with minute tubercles; style very short, hooked at the tip.—Hook. f. Handb. N.Z. Fl. 8; Kirk, Students' Fl. 20. R. sessiliflorus, R. Br. ex D.C. Syst. i. 302; Hook. f. Fl. Nov. Zel. i. 11.
North Island: Sheltered places on lava-streams. Mount Wellington and Mount Eden, &c., Auckland Isthmus; once very plentiful, but now becoming rare. Originally discovered by Mr. Colenso. September–November.
A common Australian plant, and possibly introduced from thence in the very early days of the colony. The typical state of the species, which is a much larger and stouter plant, with a very different aspect, has become naturalised in fields and waste places throughout the colony.
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. |
