A. Cunn. Precur. n. 363; Raoul, Choix, 43; Hook. f. Fl. Nov. Zel. i. 213; Handb. N.Z. Fl. 230; Benth. Fl. Austral. v. 161. C. ambiguum, R. Br. Prodr. 407.
North and South Islands, Stewart Island: Common throughout in muddy or sandy places near the sea, also occasionally found in saline localities inland. November–March.
Also occurs in Australia and Tasmania, and common in many parts of Europe and temperate Asia, &c. The New Zealand and Australian plant is sometimes kept as a separate variety or species (C. ambiguum, E. Br.), but the differences appear to be slight and inconstant.
4. C. urbicum, Linn. Sp. Plant. 218.—A coarse erect or spreading branching herb 1–2 ft. high or more, green and glabrous or rarely slightly mealy; stem angled, grooved. Lower leaves on slender petioles ½–1 in. long; blade ¾–1½ in., triangular or rhombic-ovate, coarsely and irregularly toothed and lobed, rather thin, green on both surfaces, veined; upper smaller, narrower, more acute. Flowers small, in little clusters arranged in dense leafless axillary spikes, or in terminal panicles which are leafy below. Stamens 5, exserted. Styles short. Fruiting-perianth 115 in. diam.; segments obtuse, not completely covering the utricle. Seed horizontal, much depressed, minutely punctulate, margins obtuse.—Hook. f. Fl. Nov. Zel. i. 213; Handb. N.Z. Fl. 230.
North Island: East Coast, Colenso! Has also appeared as a naturalised plant near Wellington. South Island: Not uncommon, especially in South Canterbury and Otago. Sea-level to 1000 ft. December–March.
A common European weed, which has become naturalised in North America and some other countries. It is probably not a true native of New Zealand.
5. C. ambrosioides, Linn. Sp. Plant. 219.—An erect much-branched strong-smelling glandular annual herb 1–3 ft. high; branches slender, strict, leafy. Leaves shortly petiolate, 1–4 in. long, ovate- or oblong-lanceolate to lanceolate, acute or acuminate, cuneate at the base, coarsely sinuate-toothed or -lobed, membranous, glabrous or pubescent, green, not mealy; upper ones gradually smaller, linear-lanceolate, entire or nearly so. Flowers exceedingly numerous, very minute, in little clusters in slender axillary often elongated spikes, frequently so copiously produced as to render the upper portion of the plant a large leafy panicle. Stamens 5. Styles 3–4, elongate. Fruiting-perianth about 125 in. diam., segments closed over the fruit and completely enclosing it. Seed horizontal or rarely vertical, smooth, polished, shining, margins obtuse.—Hook. f. Fl. Nov. Zel. i. 213; Handb. N.Z. Fl. 230; Benth. Fl. Austral. v. 162.
North Island: Warm lowland stations from the North Cape to Taranaki and Hawke's Bay, not common. Has also appeared as a naturalised plant near Wellington. December–April.
