Malvales
From Freepedia
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| Image:Alcea setosa.jpg Alcea setosa | ||||||||
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Bixaceae |
Malvales is an order of flowering plants, mostly comprised of shrubs and trees. Most of its families have cosmopolitan distribution in the tropics and subtropics with limited expansion into temperate regions. An interesting distribution occurs in Madagascar, where there are three endemic families of Malvales (Sphaerosepalaceae, Sarcolaenaceae and Diegodendraceae). The order accounts for about 6000 species within nine families. The dominant family is the extended Malvaceae with over 4000 species, followed by Thymelaeaceae with 750 species.
The morphology of Malvales is diverse, and there are few common characteristics. Among those most commonly encountered one can mention palmate leaves, connate sepals, and a specific structure and chemical composition of the seeds. The cortex is often fibrous, built of soft phloem layers.
Many species of Malvales are known for their wood of exceptional quality and lightness (namely Ochroma, Edgeworthia, Tilia, Thymelaea and Daphne). The cacao tree (Theobroma cacao) is used as an ingredient for chocolate. Kola nuts (Genus Cola) are notable for their high content of caffeine, and in past were commonly used for preparing of various cola drinks.
Classification
Newer systems place Malvaceae among the rosid group of dicotyledons.
The Malvaceae is taken to include the older families: Bombaceae, Sterculiaceae, and Tiliaceae. Under the older Cronquist system the order contained only these four families and 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 (1998). Circumscription of the Malvales and relationships to other Rosidae: Evidence from rbcL sequence data. American Journal of Botany 85, 876-887. (Available online: Abstract)
- W. S. Judd, C. S. Campbell, E. A. Kellogg, P. F. Stevens, M. J. Donoghue (2002). Plant Systematics: A Phylogenetic Approach, 2nd edition. pp. 405-410 (Malvales). Sinauer Associates, Sunderland, Massachusets. ISBN 0878934030.
- B. C. J. du Mortier (1829). Analyse des Familles de Plantes, avec l'indication des principaux genres qui s'y rattachent, p. 43. Imprimerie de J. Casterman, Tournay.
- B. A. Whitlock (October 2001). Malvales (Mallow). In: Nature Encyclopedia of Life Sciences. Nature Publishing Group, London. (Available online: DOI | ELS site)
