Malvaceae – Hibiscus family
Well-known members of this family include okra, cotton, and cacao.
Description of the family:
Herbs, shrubs or trees, usually with stellate hairs. Stipules present. Leaves alternate, often palmately divided. Flowers bisexual (rarely unisexual [in ours?]), actinomorphic. Epicalyx usually present, sometimes 0. Calyx (3-)5-lobed, truncate or occasionally 5- to 10-toothed. Petals 5, free. Stamens numerous, united in a tube surrounding the style. Anthers 1-thecous. Ovary superior, (1-)2-many-locular. Style often branched at apex. Fruit (in ours) either a dehiscent capsule or a schizocarp (composed of a number of mericarps arranged around a central axis).
Comment:
According to the most recent taxonomic research by the Angiosperm Phylogeny Group (APG-III), Malvaceae sensu lato now includes Bombacaceae, Tiliaceae and Sterculiaceae, three families traditionally considered closely related and in this system still treated as separate families. In this new concept Malvaceae would consist of the following nine subfamilies:
- Byttnerioideae (formerly part of Sterculiaceae, including Hermannia, Melochia and Waltheria)
- Grewioideae (formerly part of Tiliaceae including all our regional genera)
- Sterculioideae (formerly part of Sterculiaceae, including Cola and Sterculia)
- Tilioideae (formerly part of Tiliaceae Not in our region)
- Dombeyoideae (formerly part of Sterculiaceae, including Dombeya and Melhania)
- Brownlowioideae (formerly part of Tiliaceae Not in our region)
- Helicteroideae (formerly part of Sterculiaceae, including Triplochiton)
- Malvoideae (formerly Malvaceae sensu stricto, as used here)
- Bombacoideae (formerly Bombacaceae)
However, this circumscription of the Malvaceae is still controversial. The relationships between these subfamilies are still either poorly supported or almost completely obscure, so that the very definition of the family may change dramatically as new studies are published. We therefore prefer to use the old concept and still treat the 4 families separately with the traditional Malvaceae sensu stricto, as listed below, comprising a very homogeneous and cladistically monophyletic group.
Worldwide:
78 genera and 1,670 species, cosmopolitan but especially in the tropics.
Zimbabwe:
13 genera and 96 taxa.
- Abelmoschus Medik.
- Abutilon Mill.
- Azanza Alef.
- Cienfuegosia Cav.
- Gossypium L.
- Hibiscus L.
- Kosteletzkya C. Presl
- Malva L.
- Malvastrum A. Gray
- Pavonia Cav.
- Sida L.
- Urena L.
- Wissadula Medik.
