Common name. Spyridiums. Family Rhamnaceae.
Habit and leaf form. Shrubs. ‘Normal’ plants. Leaves well developed. Plants with roots; non-succulent; unarmed; autotrophic. To 4 m high (in Australia). Self supporting. Not heterophyllous. Leaves small, or medium-sized; not fasciculate; alternate; with blades; petiolate; with ‘normal’ orientation; simple; not peltate. Leaf blades entire; flat, or folded (lengthwise); variously shaped; pinnately veined. Mature leaf blades adaxially glabrous, or scabrous; abaxially pubescent (densely and shortly white stellate hairy or sericeous). Leaves with stipules. Stipules scaly; persistent. Leaf blade margins entire; flat, or unknown. Leaf anatomy. Hairs present, or absent; complex hairs present, or absent. Complex hairs stellate.
Reproductive type, pollination. Fertile flowers hermaphrodite. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence and flower features. Flowers aggregated in ‘inflorescences’; in heads, or in corymbs. Inflorescences simple, or compound. The terminal inflorescence unit cymose. Inflorescences terminal, or axillary. Flowers subsessile, or sessile; bracteate; minute; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; glabrous, or hairy; valvate; regular. Calyx lobes triangular, or ovate. Epicalyx absent. Corolla present (small); 5; 1 -whorled; alternating with the calyx; polypetalous; regular. Petals clawed. Androecium present. Fertile stamens present. Androecial members definite in number. Androecium 5. Androecial members adnate; free of the gynoecium (inserted near the disc); free of one another; 1 -whorled. Stamens 5; all more or less similar in shape; isomerous with the perianth; alternisepalous; filantherous. Anthers separate from one another; dehiscing via longitudinal slits; bilocular; tetrasporangiate. Fertile gynoecium present. Gynoecium 3 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium syncarpous; synstylovarious; inferior. Ovary plurilocular; 3 locular. Ovary summit hairy, the hairs not confined to radiating bands. Gynoecium stylate. Styles 1; apical. Stigmas 3 - lobed. Ovules 1 per locule (in WA); ascending; anatropous.
Fruit and seed features. Fruit aerial; 2–3 mm long; hairy; a schizocarp. Dispersal unit the seed, or the fruit. Seeds 1 per locule. Seeds small; arillate.
Geography, cytology, number of species. Native of Australia. Endemic to Australia. Australian states and territories: Western Australia, South Australia, Northern Territory, New South Wales, Victoria, and Tasmania. South-West Botanical Province. A genus of ca 30 species; ca 15 species in Western Australia; 2 endemic to Western Australia.
Etymology. From the Greek for "a small basket"; the tiny flower heads are surrounded by leafy bracts.