MalvalesStacey D. Smith and David A. Baum
This tree diagram shows the relationships between several groups of organisms.
The root of the current tree connects the organisms featured in this tree to their containing group and the rest of the Tree of Life. The basal branching point in the tree represents the ancestor of the other groups in the tree. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.
You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.close box
Phylogeny of expanded Malvales based on Bayer et al. (1999) and Alverson et al. (1998). Core Malvales includes the taxa traditionally placed in the Bombacaceae, Malvaceae, Sterculiaceae and Tiliaceae.
The order Malvales has traditionally included four core families, Bombacaceae, Malvaceae, Sterculiaceae and Tiliaceae, although various authors have included other families such as Cistaceae and Cochlospermaceae. Recent phylogenetic studies (e.g., Alverson et al. 1998, Bayer et al. 1999) have revealed that the four core families form a monophyletic group, termed here the core Malvales, and have identified ten allied families which are included in the expanded Malvales shown in the tree above. Together, these families contain approximately 4,000 species and range from small Mediterranean shrubs like Cistus to towering tropical trees like Shorea. The order also contains many economically important plants, such as Cola (the source of cola flavor), Bixa orellana (annatto, a natural red coloring), Theobroma cacao (the source of cocoa) and Gossypium (cotton) and Ochroma pyramidale (balsa wood).
Many members of Malvales can be identified by the following combination of characters: leaves with palmate venation (often three principal veins arising from the base of the leaf blade), mucilage canals within the tissues (think of the slime in Okra), stellate (star-shaped) hairs on the vegetative parts of the plant and stipules (leaf-like structures at the base of the leaf stalk).
The core Malvales clade has been consistently well-supported in molecular phylogenetic analyses as have the clades comprising Bixaceae+Diegodendraceae+Cochlospermaceae and Dipterocarpaceae+Sarcolaenaceae+Cistaceae. However, placement of the remaining families (Muntingiaceae, Sphaerosepalaceae, Thymelaceae and Neuradaceae) is still unclear. Muntingiaceae falls either in the Dipterocarpaceae+Sarcolaenaceae+Cistaceae clade (Alverson et al. 1998, Fay et al. 1998) or at the base of the Malvales (Bayer et al. 1999). Analyses by Alverson et al. (1998) place Sphaerosepalaceae basal in the Bixaceae+Cochlospermaceae clade (Diegodendraceae was not sampled in their analysis). In contrast, Bayer et al. (1999) found that Sphaerosepalaceae falls sister to Thymelaeaceae, but with weak support. Thymelaeaceae (+Sphaerosepalaceae) has been weakly supported as sister to the Dipterocarpaceae+Sarcolaenaceae+Cistaceace+Muntingiaceae (Alverson et al. 1998, Bayer et al. 1999). Finally, Neuradaceae seems most likely to belong at the base of the Malvales, although no studies have been able to place it with certainty.
Alverson, W. S., K. G. Karol, D. A. Baum, M. W. Chase, S. M. Swensen, R. McCourt, and K. J. Sytsma. 1998. Circumscription of the Malvales and relationships to other Rosidae: Evidence from rbcL sequence data. American Journal of Botany 85:876-887.
Bayer, C., M. F. Fay, A. Y. De Bruijn, V. Savolainen, C. M. Morton, K. Kubitzki, W. S. Alverson, and M. W. Chase. 1999. Support for an expanded family concept of Malvaceae with a recircumscribed order Malvales: a combined analysis of plastid atpB and rbcL DNA sequences. Botanical Journal of the Linnean Society 129:267-303.
Fay, M. F., C. Bayer, W. S. Alverson, A. Y. de Bruijn, and M. W. Chase. 1998. Plastid rbcL sequence data indicate a close affinity between Diegodendron and Bixa. Taxon 47:43-50.
Correspondence regarding this page should be directed to Stacey D. Smith at
Page copyright © 2009 and
Page: Tree of Life Malvales. Authored by Stacey D. Smith and David A. Baum. The TEXT of this page is licensed under the Creative Commons Attribution License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.
- First online 20 March 2003
Citing this page:
Smith, Stacey D. and David A. Baum. 2003. Malvales. Version 20 March 2003 (under construction). http://tolweb.org/Malvales/21050/2003.03.20 in The Tree of Life Web Project, http://tolweb.org/