Herissantia Medik.
Philos.Bot. 1:90 (1789)

Name Status: Current
Browse to the list of specimens for Herissantia Medik.

Scientific Description
S. Hamilton-Brown, Thursday 8 September 2016

Family Malvaceae.

Tribe Malveae.

Habit and leaf form. Spreading herbs (with an indumentum of stellate hairs or simple hairs). Plants unarmed. Annual, or perennial. Mesophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple. Leaf blades dorsiventral; entire; ovate; palmately veined; cordate. Mature leaf blades adaxially pubescent; abaxially pubescent. Leaves with stipules (stipules subulate). Leaf blade margins crenate. Leaf anatomy. Hairs present; complex hairs present. Complex hairs stellate. Extra-floral nectaries absent.

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

Inflorescence and flower features. Flowers solitary; axillary; pedicellate (pedicels articulate); small; regular; 5 merous; tetracyclic. Hypogynous disk absent. Perianth with distinct calyx and corolla; 10; 2 -whorled; isomerous. Calyx present; 5; 1 -whorled; gamosepalous; lobed; lobulate (deeply 5-lobed); hairy; valvate; exceeded by the corolla; regular. Calyx lobes triangular. Epicalyx absent. Corolla present; 5; 1 -whorled; polypetalous (adnate to the base of the staminal column); white, or yellow. Petals obovate. Androecium present. Androecial members indefinite in number. Androecium 50–100 (i.e. ‘many’). Androecial members adnate; all equal; coherent (connate; the filaments fused in a column surrounding the style); 1 - adelphous (the tube attached to the petals); 1 -whorled. Androecium exclusively of fertile stamens (or rather, half-stamens, each having only a half anther). Stamens 50–100. Anthers dehiscing via longitudinal slits; introrse; unilocular. Gynoecium 8–15 carpelled (in a single whorl). The pistil 8–15 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 8–15 locular. Gynoecium stylate. Styles 1; more than 4-branched (8–15-branched, i.e. as many as the carpels); apical. Stigmas 8–15. Placentation axile. Ovules 2–10 per locule (i.e. 2-several).

Fruit and seed features. Fruit 5–6 mm long; non-fleshy; hairy, or not hairy; a schizocarp (separating septicidally into 2-valved mericarps leaving a persistent central axis). Mericarps 8–15. Dispersal unit the mericarp (reniform in outline, laterally compressed, inflated, membranous-chartaceous, the outer edge awned). Seeds 2 or more per mericarp. Seeds conspicuously hairy.

Geography, cytology, number of species. World distribution: America and Australia. Adventive. Australian states and territories: Western Australia and Northern Territory. Northern Botanical Province. A genus of c. 5 species; 1 species in Western Australia; 0 endemic to Western Australia.

Additional comments. Often placed in the genus Abutilon. Etymology: commemorates Louis Antoine Prospere Herissant, 1745–1769, a French physician, naturalist and poet.

Taxonomic Literature

  • Wheeler, J. R.; Rye, B. L.; Koch, B. L.; Wilson, A. J. G.; Western Australian Herbarium (1992). Flora of the Kimberley region. Western Australian Herbarium. Como, W.A.