Page:Manual of the New Zealand Flora.djvu/65

The usual form of this species, with very long petioles and broad leaf-segments, has a very distinct appearance; but small varieties are difficult to distinguish from R. rivularis, var. major. Mr. Colenso's R. longipetiolatus, judging from the specimens in his herbarium, cannot be separated even as a variety.

33. R. rivularis, Banks and Sol. ex Forst. Prodr. n. 524.—Smooth, perfectly glabrous in all its parts. Stems creeping, often branched and forming broad matted patches, rooting at the nodes and giving off tufts of radical leaves and erect pedurxles or weak sparingly branched flowering-stems, or floating and irregularly branched. Leaves on slender petioles 1–6 in. long; blade ¹⁄₄–1¹⁄₂ in. diam., ovate semicircular or reniform in outline, usually 3–7-partite to the base; segments varying from cuneate to narrovp-linear, more or less deeply cut at the apex, sometimes to the middle, occasionally ternatisect, rarely entire. Peduncles usually longer than the leaves. Flowers yellow, ¼–¾ in. diam. Sepals 5, spreading. Petals 5–10, linear-oblong, usually longer than the sepals; gland some distance above the base. Achenes turgid, glabrous, sometimes rugose from the shrivelling of the epicarp; style rather long, subulate, straight or recurved.—A. Cunn. Precur. n. 630; Raoul, Choix de Plantes, 47; Hook. f. Fl. Nov. Zel. i. 11; Handb. N.Z. Fl. 8; Kirk, Students' Fl. 18.

Var. major, Benth. Fl. Austral. i. 14.—Suberect, 3–12 in. high. Leaves tufted; segments often very narrow and much cut.—R. incisus. Hook. f. Fl. Nov. Zel. i. 10, t. 4. R. amphitricha, Colenso in Trans. N.Z. Inst. xvii. (1885) 237.

Var. subfluitans, Benth. l.c.—Creeping or partially floating. Leaves smaller, less divided. Flowers and achenes smaller.—R. inundatus, R. Br. ex D.C. Syst. i. 269; Hook. f. Fl. Tasm. i. 8.

Var. inconspicuus, Benth. l.c.—Smaller, more slender, suberect. Leaf-segments 3 fid. Flowers smaller.—R. inconspicuus. Hook. f. Fl. Tasm. i. 8,. t. 2b.

North, South, Stewart, and Chatham Islands: Common in swamps and streams, &c., ascending to 2500 ft. Var. inconspicuus: Pencarrow Lagoon, near Wellington, Kirk! Otago, Petrie! October–March. Also plentiful in Australia.

A most abundant little plant, exceedingly variable in most of its characters, and particularly so in the extent to which the leaves are divided, and the width or narrowness of the ultimate segments. Stock owners consider it to be highly poisonous, and attribute to it many deaths occurring among cattle feeding in swamps in dry summers.

34. R. acaulis, Banks and Sol. ex D.C. Syst. i. 270.—Small, dark-green, fleshy, perfectly glabrous, sending out creeping stolons and often forming broad matted patches. Leaves all radical, on slender petioles 1–3 in. long; blade ½–¾ in. diam., trifoliolate or deeply 3-lobed; leaflets or segments sessile, obovate or oblong, obtuse, entire or 2–3-lobed. Scapes shorter than the leaves, naked, 1-flowered. Flowers small, ¼–⅓ in. diam. Sepals 5, roundish-ovate,