Spergularia (Pers.) J.Presl & C.Presl

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, or biennial, or perennial. Leaves cauline. To 0.1–0.3 m high. Self supporting. Mesophytic (or rarely halophytic). Not heterophyllous. Leaves small, or medium-sized; fasciculate; opposite, or whorled (apparently); with blades, or bladeless (filiform); fleshy; sessile; not connate; simple; not peltate. Leaf blades entire; linear (to filiform). Mature leaf blades adaxially sparsely glandular pubescent; abaxially sparsely glandular pubescent. Leaves with stipules (4 at each node). Stipules concrescent (connate); ochreate; scaly (‘scarious’); caducous. Leaf blade margins entire. Leaf anatomy. Hairs present; glandular hairs present.

Reproductive type, pollination. Fertile flowers hermaphrodite, or functionally male and functionally female. Unisexual flowers absent, or present (rarely). Plants hermaphrodite, or monoecious.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in cymes. Inflorescences compound. The terminal inflorescence unit cymose. Inflorescences terminal; without involucral bracts. Flowers pedicellate; small; regular; tetracyclic, or tricyclic (rarely). Free hypanthium present (‘subperigynous’). Perianth with distinct calyx and corolla, or sepaline (rarely); 10, or 5 (rarely); 2 -whorled, or 1 -whorled (rarely); isomerous, or anisomerous (when corolla 0). Calyx present; 5; 1 -whorled; polysepalous; hairy (glandular-hairy); imbricate, or valvate (rarely). Corolla present, or vestigial (rarely), or absent (rarely); 0, or 5; 0 -whorled, or 1 -whorled; polypetalous; contorted, or imbricate (rarely); white, or pink, or purple (‘mauve’). Petals oblong to obovate; sessile. Corolla members entire. Androecium present. Fertile stamens present. Androecium 1–10. Androecial members markedly unequal (when stamens 10, the episepalous stamens longer), or all equal; free of one another; 1 -whorled, or 2 -whorled. Androecium exclusively of fertile stamens. Stamens 1–10; reduced in number relative to the adjacent perianth, or isomerous with the perianth, or diplostemonous (obdiplostemonous); oppositisepalous. Anthers separate from one another; dehiscing via longitudinal slits; introrse; bilocular; tetrasporangiate. Fertile gynoecium present, or absent. Gynoecium 3(–5) carpelled. The pistil 1 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary unilocular; 1 locular. Gynoecium stylate. Styles 3(–5); free, or partially joined; simple. Stigmas 3(–5) - lobed. Placentation free central, or basal. Ovules campylotropous.

Fruit and seed features. Fruit 3–7 mm long; dehiscent; a capsule. Capsules valvular. Dispersal unit the seed. Fruit 50 seeded (‘numerous’). 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, Northern Territory, Queensland, New South Wales, Victoria, Australian Capital Territory, and Tasmania. 2n=18, 36, 54, 72. A genus of ca 40 species; 3 species in Western Australia; 0 endemic to Western Australia.

Additional comments. Seeds of some species are used as famine food (Bittrich 1993:217).