Lavatera L.

Scientific Description

Common name. Hollyhocks. Family Malvaceae.

Tribe Malveae.

Habit and leaf form. Shrubs, or herbs (often densely stellate-hairy). Plants unarmed. Annual, or perennial; to 0.1–4 m high. Mesophytic. Heterophyllous (the leaves subtending the inflorescence often smaller and more or less unlobed). Leaves medium-sized; alternate; spiral; petiolate; non-sheathing; simple. Leaf blades dorsiventral; dissected (5–9-lobed); ovate, or orbicular (to reniform); palmately lobed; palmately veined. Mature leaf blades adaxially pubescent; abaxially pubescent. Leaves with stipules (stipules membranous to herbaceous). Stipules persistent. Leaf blade margins crenate, or serrate. Leaf anatomy. Hairs present; complex hairs present. Complex hairs stellate.

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

Inflorescence and flower features. Flowers solitary, or aggregated in ‘inflorescences’; axillary; in racemes, or in panicles. Inflorescences terminal. Flowers pedicellate; 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 (5-lobed, lobes more or less acute); hairy; valvate; exceeded by the corolla (petals 2–3 times as long as the calyx); campanulate, or tubular; regular; persistent; accrescent. Calyx lobes triangular. Epicalyx present (of rounded to ovate bracteoles, connate towards the base). Corolla present; 5; 1 -whorled; polypetalous (adnate to the base of the staminal column; petals notched); white, or red, or pink, or purple (or lilac), or blue. Androecium present. Androecial members indefinite in number. Androecium 50–100 (i.e. ‘many’). Androecial members adnate (the column much shorter than the petals); 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 5–16 carpelled. The pistil 5–16 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 5–16 locular. Gynoecium stylate. Styles 5–16 (styles separating into filiform style branches, stigmatic along the inner surface); more than 4-branched; apical. Stigmas 5–16. Placentation axile. Ovules 1 per locule.

Fruit and seed features. Fruit 6–8 mm long; non-fleshy; hairy, or not hairy; a schizocarp (discoid, umbilicate dehiscing into dehiscent mericarps arranged in a whorl around the conical receptacle, dehiscent apparently by abscission of the disc, i.e. circumciss). Mericarps 5–16. Dispersal unit the mericarp (reniform). Seeds 1 per mericarp.

Geography, cytology, number of species. World distribution: Mediterranean to East Asia and Australia. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, South Australia, Northern Territory, Queensland, New South Wales, Victoria, and Australian Capital Territory. South-West Botanical Province. 2n = 14 for L. phoenicea and L. trimestris; 2n = 40–44 for L. acerfolia, L. arborea, L. assurgentiflora, L. cashmiriana, L. maritima, L. oblongifolia, L. occidentalis, L. plebeia, L. thuringiaca; 2n = 84 for L. mauritanica and 2n = 112 for L. cretica. A genus of c. 25 species; 4 species in Western Australia; 0 endemic to Western Australia.

Etymology. Named for members of the Lavater family of physicians and naturalists of Zu"rich.