Common name. Buttercups. Family Ranunculaceae.
Subfamily Ranunculoideae, Tribe Ranunculeae.
Habit and leaf form. Herbs. ‘Normal’ plants. Leaves well developed. Plants with roots; unarmed; autotrophic. Annual, or perennial. Leaves basal, or cauline. Self supporting. Hydrophytic, or mesophytic; rooted. Leaves submerged. Not heterophyllous, or heterophyllous. Leaves medium-sized, or small; alternate; spiral, or unknown; with blades; ‘herbaceous’, or leathery; petiolate; simple, or compound; ternate, or pinnate. Leaf blades neither inverted nor twisted through 90 degrees; dissected; flat; variously shaped; pinnately veined. Mature leaf blades adaxially glabrous, or scabrous; abaxially glabrous, or scabrous. Leaves with stipules, or without stipules. Leaf blade margins entire, or crenate. Leaf anatomy. Hairs present, or absent.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite. Plants homostylous.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’, or solitary; terminal. Inflorescence many-flowered, or few-flowered. Flowers in cymes. Inflorescences compound, or simple. The terminal inflorescence unit cymose. Flowers subsessile, or sessile; small; regular; not resupinate; 5 merous (usually). Free hypanthium absent. Perianth with distinct calyx and corolla; (8–)10(–25); 2 -whorled; isomerous, or anisomerous. Calyx present; 3–5; 1 -whorled; polysepalous. Corolla (honey leaves) present; (3–)5–8(–20); 1 -whorled; appendiculate (with a basal nectiferous pit near the base on the upper side); polypetalous. Androecium present. Fertile stamens present. Androecial members indefinite in number, or definite in number. Androecium 100 (‘numerous’). Stamens 100 (‘numerous’); triplostemonous to polystemonous; filantherous. Anthers separate from one another; dehiscing via longitudinal slits; tetrasporangiate; yellow. Fertile gynoecium present. Gynoecium 100 carpelled (‘numerous’). The pistil 100 celled (‘numerous’). Carpels increased in number relative to the perianth. Gynoecium syncarpous; synovarious; superior. Ovary plurilocular; 100 locular (‘numerous’). Gynoecium stylate. Styles simple; apical; persistent, or deciduous (rarely). Stigmas 1 - lobed. Ovules 1 per locule.
Fruit and seed features. Fruit 1–2 mm long; indehiscent; achene-like. Dispersal unit the seed. Seeds endospermic.
Geography, cytology, number of species. Native of Australia, or adventive. Endemic to Australia, or not endemic to Australia. Australian states and territories: Western Australia, South Australia, Queensland, New South Wales, Victoria, Australian Capital Territory, and Tasmania. South-West Botanical Province. A genus of ca 300 species; 7 species in Western Australia; 1 endemic to Western Australia.
Etymology. From the Latin ranunculus (small frog); humourously applied to dwellers near a marsh; also applied by Pliny to four species of this genus on account of their habitat.