• Malvaceae Taxonomy •
Taxonomy (from the Greek τάξις, [taxis], for order, arrangement) is the branch of science concerned with the classification of organisms, systematically arranging them in a defined order. For additional information on this topic, see Botanical Latin.
The Malvaceae family presents many challenges for taxonomists. Opinions often differ as where to draw the lines between species, between genera, between tribes and between the subfamilies. This is not surprising —the Malvaceae family encompasses over 200 genera with close to 2,300 species! In terms of number of species, the largest genera include Hibiscus (~300 species), Sterculia (~250 species), Dombeya (~225 species), Pavonia (~200 species) and Sida (~200 species).
In recent years an expanded circumscription of the Malvaceae family has been created, which is composed of nine subfamilies. The relationships between these subfamilies are still obscure, and the subject of ongoing discussion. The traditional Malvaceae have been moved to Malvoideae, the subfamily that now approximately corresponds to that group.
The Nine Subfamilies of Malvaceae
Bombacoideae: (formerly Bombacaceae, in part), 12 genera, (~120 species).
Brownlowioideae: 8 genera, (~70 species).
Byttnerioideae: 26 genera, (~650 species).
Dombeyoideae: About 20 genera, (~380 species).
Grewioideae: 25 genera, (~770 species).
Helicteroideae: 8 to 12 genera, 10 to 90 species.
Sterculioideae: (formerly Sterculiaceae, in part), 12 genera, (~430 species).
Tilioideae: (formerly Tiliaceae, in part) 3 genera, (~50 species).
Malvoideae: (formerly Malvaceae), 78 genera, (~1,600 species). Temperate to tropical distribution. Subfamily Malvoideae now comprises the traditional Malvaceae and has consistently emerged as a very homogeneous, monophyletic group. In a recent treatment of Malvoideae, Bayer and Kutbitzki (2003) divide the subfamily into four tribes: Gossypieae, Hibisceae, Kydieae, and Malveae. The Malvoideae can be further ranked into the tribes listed below:
Malvoideae Tribes