Polycarpon L.

Scientific Description

Family Caryophyllaceae.

Subfamily Paronychioideae, Tribe Polycarpeae.

Habit and leaf form. Herbs; non-laticiferous and without coloured juice. ‘Normal’ plants. Leaves well developed. Plants with roots. Annual to perennial (without a woody stock in Australia). Leaves cauline. To 0.25 m high. Self supporting. Mesophytic. Not heterophyllous. Leaves small; opposite, or whorled (apparently); with blades; ‘herbaceous’, or fleshy (rarely); sessile; simple; not peltate. Leaf blades entire; obovate to orbicular. Mature leaf blades adaxially glabrous; abaxially glabrous. Leaves with stipules. Stipules scaly (‘scarious’). Leaf blade margins entire; flat. Leaf anatomy. Hairs absent; glandular hairs absent.

Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes. Inflorescences compound. The terminal inflorescence unit cymose. Inflorescences terminal; in cymose clusters. Flowers pedicellate; scarious bracteate; small; regular; tetracyclic, or tricyclic (rarely). Free hypanthium present (subperigynous). Perianth with distinct calyx and corolla, or sepaline (rarely); (5–)10; 2 -whorled, or 1 -whorled (rarely); isomerous, or anisomerous (rarely). Calyx present; 5; 1 -whorled; polysepalous; glabrous; imbricate, or valvate (rarely). Corolla present, or absent; (0–)5; 0 -whorled, or 1 -whorled; polypetalous; contorted, or imbricate (rarely). Petals oblong to obovate; sessile. Corolla members entire. Androecium present. Fertile stamens present. Androecium 1–5 (episepalous). Androecial members markedly unequal; free of one another; 1 -whorled, or 2 -whorled. Androecium exclusively of fertile stamens. Stamens 1–5; isomerous with the perianth, or diplostemonous (obdiplostemonous); oppositisepalous. Anthers separate from one another; dehiscing via longitudinal slits; introrse; bilocular; tetrasporangiate. Fertile gynoecium present. Gynoecium 1 carpelled. The pistil 1 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary unilocular; 1 locular. Gynoecium stylate. Styles 1; partially joined; simple. Stigmas 3 - lobed. Placentation free central, or basal. Ovules campylotropous.

Fruit and seed features. Fruit ca 1.5 mm long; not hairy; dehiscent; a capsule. Capsules valvular. Dispersal unit the seed. Fruit ca 15 seeded. Perisperm present. Seeds small, or minute.

Geography, cytology, number of species. Holarctic. Adventive. Not endemic to Australia. Australian states and territories: Western Australia, South Australia, Queensland, New South Wales, Victoria, and Tasmania. South-West Botanical Province. 2n=14, 16, 18, 32, 36, 64. A genus of ca 16 species; 1 species in Western Australia; 0 endemic to Western Australia.

Additional comments. P. spirostylis is a copper indicator in Australia (Bittrich 1993:221).