5. PARIETARIA, Tourn.
Annual or perennial herbs. Leaves alternate, petiolate, quite entire, 3-nerved; stipules wanting. Flowers polygamous, in axillary cymes or glomerules, sessile, bracteate. Male flowers (often hermaphrodite): Perianth deeply 3–4-partite; segments valvate. Stamens 3–4, inflexed in bud. Female flowers: Perianth tubular at the base, 3–4-lobed. Ovary free within the perianth; stigma recurved, penicillate; ovule solitary, erect. Achene enclosed in the variously enlarged persistent perianth, crustaceous. Seed albuminous; cotyledons oblong or ovate.
A small genus of 7 or 8 species, generally distributed in both temperate and tropical regions. The single New Zealand species has almost the range of the genus.
1. P. debilis, Forst. Prodr. n. 387.—A slender flaccid more or less pubescent diffusely branched annual herb 6–18 in. high. Leaves on long slender petioles; blade ½–1½ in. long, broadly ovate or ovate-cordate, obtuse or obtusely acuminate, thin and membranous, quite entire, green on both surfaces, 3-nerved from the base. Cymes 3–7-flowered, almost contracted into sessile clusters; bracts linear, shortly united at the base. Hermaphrodite (or male) flowers usually in the fork of the cyme; perianth almost unchanged in fruit. Female flowers lateral; perianth evidently enlarged in fruit. Achene very minute, dark-brown, quite smooth.—A. Rich. Fl. Nouv. Zel. 354; Hook. f. Fl. Nov. Zel. i. 226; Handb. N.Z. Fl. 252; Benth. Fl. Austral. vi. 188. Urtica debilis, Endl. Prodr. Fl. Norfolk. 37; A. Cunn. Precur. n. 334; Raoul, Choix, 42.
Kermadec Islands, North and South Islands: Abundant as far south as middle Otago. Sea-level to 2500 ft. Flowers spring and summer.
6. AUSTRALINA, Gaud.
Diffuse or creeping annual or perennial herbs. Leaves alternate, petiolate, crenate-toothed or almost entire; stipules lateral, free. Flowers monœcious, in few-flowered axillary glomerules; glomerules unisexual or androgynous. Male flowers: 1–5 together at the summit of a common peduncle. Perianth irregularly bilabiate, the outer lip inflexed in bud. Stamen solitary. Rudimentary ovary wanting. Female flowers solitary or few together, sessile. Perianth ovoid-tubular, mouth contracted and obscurely toothed. Ovary free within the perianth; stigma linear, villous; ovule erect from the base. Achene enclosed in the persistent perianth; pericarp thin, shining. Seed with scanty albumen; cotyledons ovate.
A small genus of 6 species, 2 found in Australia, 1 of them extending to New Zealand, and 4 natives of South Africa and Abyssinia.
