The Malvales are an order of flowering plants. As circumscribed by APG
II-system, the order includes about 6000 species within 9 families. The order is
placed in the eurosids II, which are part of the eudicots.
The plants are mostly shrubs and trees; most of its families have a cosmopolitan
distribution in the tropics and subtropics, with limited expansion into
temperate regions. An interesting distribution occurs in Madagascar, where
three endemic families of Malvales occur.
Many species of Malvaceae sensu lato are known for their wood, with that of
Ochroma being known for its lightness, and that of Tilia as a popular wood for
carving. Fruit of the cacao tree are used as an ingredient for chocolate.
Kola nuts are notable for their high content of caffeine, and in past were
commonly used for preparing of various cola drinks. Other well-known members of
Malvales in the APG II sense are daphnes, hibiscus, hollyhocks, okra,
baobab trees, cotton, and kapok. The morphology of Malvales is diverse,
with few common characteristics. Among those most commonly encountered are
palmate leaves, connate sepals, and a specific structure and chemical
composition of the seeds. The cortex is often fibrous, built of soft phloem
layers. Classification
Family boundaries and circumscriptions of the "core" Malvales families,
Malvaceae, Bombacaceae, Tiliaceae, and Sterculiaceae, have long been
problematic. A close relationship among these families, and particularly
Malvaceae and Bombacaceae, has generally been recognized, although until recently
most classification systems have maintained them as separate families.
With numerous molecular phylogenies showing Sterculiaceae, Bombacaceae, and
Tiliaceae as traditionally defined are either paraphyletic or polyphyletic, a
consensus has been emerging for a trend to expand Malvaceae to include these
three families. This expanded circumscription of Malvaceae has been
recognized in the most recent version of the Thorne system, by the Angiosperm
Phylogeny Group, and in the most recent comprehensive treatment of vascular
plant families and genera, the Kubitzki system.
The dominant family in the APG II-system is the extended Malvaceae with over 4000
species, followed by Thymelaeaceae with 750 species. This expanded
circumscription of Malvaceae is taken to include the families Bombacaceae,
Sterculiaceae and Tiliaceae. Under the older Cronquist system the order
contained these four "core Malvales" families plus the Elaeocarpaceae and was
placed among the Dilleniidae. Some of the currently included families were
placed by Cronquist in the Violales. References
Alverson, W. S., K. G. Karol, D. A. Baum, M. W. Chase, S. M. Swensen, R.
McCourt, and K. J. Sytsma. Circumscription of the Malvales and
relationships to other Rosidae: Evidence from rbcL sequence data. American
Journal of Botany 85, 876-887. Edlin, H. L. 1935. A critical revision
of certain taxonomic groups of the Malvales. New Phytologist 34: 1-20,
122-143. Judd, W.S., C. S. Campbell, E. A.
Kellogg, P. F. Stevens, M. J. Donoghue. Plant Systematics: A Phylogenetic
Approach, 2nd edition. pp. 405–410. Sinauer Associates, Sunderland,
Massachusetts. ISBN 0-87893-403-0. Kubitzki, K. and M. W. Chase. 2003.
Introduction to Malvales, pp. 12– 16. In K. Kubitzki, The Families and Genera of
Vascular Plants, vol. 5, Malvales, Capparales and non-betalain
Caryophyllales. du Mortier, B. C. J.. Analyse des
Familles de Plantes, avec l'indication des principaux genres qui s'y
rattachent, p. 43. Imprimerie de J. Casterman, Tournay.
Watson, L., and Dallwitz, M. J.. The families of flowering plants:
descriptions, illustrations, identification, and information
retrieval. http:delta-intkey.com Whitlock, B. A.. Malvales. In: Nature
Encyclopedia of Life Sciences. Nature Publishing Group, London.
External links Tree of Life Malvales