The Malvaceae includes over 100 genera and perhaps 2 000 species. Its greatest diversity is in the tropics and subtropics; a few genera are characteristic of the temperate zones. On a world-wide basis. the family includes four large genera (Sida, Abutilon, Hibiscus, and Pavonia), all four of which are represented in Chiapas. The family is richly developed in South America and has other major centers of diversity in Mexico, Africa, and Australia. In Mexico 54 genera are known, of which 37 are reported from Chiapas. and four (Abelmoschus, Malva, Alcea, and Lavatera) are introduced. Certain genera, especially Hampea, Dendrosida, and Robinsonella, have their principal diversity in Chiapas and adjacent regions. Interestingly, all three of these genera are characteristically arborescent, a growth form that is exceptional in the family.
The format of the present treatment essentially follows that established by Smith in the Pteridophyte volume of the present series.