Malvaceae
Encyclopedia : M : MA : MAL : Malvaceae
| The [Neutral point of view>neutrality] of this article is [NPOV disputedisputed]. Please see the discussion on the [flowering plants containing Malva, the mallow genus, and its relatives. There are two main views on the circumscription of the family. One view takes the traditionally narrow view of the family, Malvaceae sensu stricto. The APG II system takes a broader circumscription on the basis of molecular phylogenies that show that while Malvaceae s.s. is cladistically monophyletic, several closely related families of order Malvales are not monophyletic. This definition of the family unites the core Malvales of the Cronquist system, including Bombacaceae, Malvaceae s.s., Sterculiaceae and Tiliaceae, into the wider Malvaceae sensu lato.
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Malvaceae sensu strictoThat Malvaceae s.s. comprise a cladistically monophyletic group has been confirmed by recent molecular phylogenies. It is a homogeneous taxon, so homogeneous that the subfamily category is not applicable, Malvaceae s.s. is only subdivided in tribes.The family most closely related to Malvaceae s.s. is Bombacaceae, and the two are separated primarily on the basis of pollen characters (smooth or rugose in Bombacaceae, spiny in Malvaceae). Malvaceae s.s. also tend to be herbs or shrubs, whereas Bombacaceae are usually trees. Molecular phylogenies have demonstrated that Bombacaceae is cladistically paraphyletic with respect to Malvaceae s.s. It has been recognised by most compilers of high-level classifications, including:
Malvaceae is still accepted in its restricted sense in several nomenclatural compilations: at IK, APNI (Australian Plant Names Index) and GCI (Gray Card Index) at [IPNI] (see also list of systems of plant taxonomy); and in several herbaria of the whole world, besides being the classification "standard" of many reference works such as manuals, floras and very important: identification keys (see [Thonner's analytical key to the families of flowering plants]). A different approach was taken by Edlin (1935), who restricted Malvaceae even further by transferring the genera with capsular fruits, including Gossypium and Hibiscus, into a more broadly defined Bombacaceae. Malvaceae sensu stricto as traditionally defined consists of about 111-119 genera, totalling about 1,500 species. This includes the mallows, cotton plants, okra, hibiscus, and hollyhocks. GeneraSource: Royal Botanic Gardens, Kew
Malvaceae sensu latoIn the broader APG circumscription, the Malvaceae are also a cladistically monophyletic group but take in a much larger number of genera. Because molecular phylogenies have shown that Bombacaceae, Tiliaceae, and Sterculiaceae as traditionally defined are closely related to Malvaceae s.s. but are not monophyletic groups, Malvaceae have been expanded to include these families. This expanded definition has been adopted by numerous researchers on the Malvales (e.g., Baum et al. 2004, Perveen et al. 2004, Tate et al. 2005).Whether a consensus in favor of a broad or narrow circumscription of Malvaceae will be adopted, or something in between, remains to be seen. The broad circumscription of Malvaceae has been adopted in textbooks on plant systematics (Judd et al. 1999), in a comprehensive treatment of vascular plant families and genera, the Kubitzki system, by Bayer & Kubitzki (2003), and in a treatment of Neotropical plant families by Maas & Westra (2005). The most recent version of the Thorne system takes an intermediate approach in combining Bombacaceae and Sterculiaceae under Malvaceae, but retaining Byttneriaceae (containing elements of the traditional Sterculiaceae and Tiliaceae) and a considerably restricted Tiliaceae as separate families. Malvaceae sensu APG is a family of about 250 genera; it thus also includes lindens, kapok, baobabs, balsa, etc. There are nine subfamilies (Bayer et al. 1999, Bayer & Kubitzki 2003):
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