The plants are mostlyshrubs andtrees; most of its families have acosmopolitan distribution in thetropics andsubtropics, with limited expansion intotemperate regions. An interesting distribution occurs inMadagascar, where three endemic families of Malvales (Sphaerosepalaceae, Sarcolaenaceae and Diegodendraceae) occur.
Many species of Malvaceae,sensu lato (in the broad sense), are valued for their wood, with that ofOchroma (balsa) being known for its lightness, and that ofTilia (lime, linden, or basswood) as a popular wood for carving. Fruit of the cacao tree (Theobroma cacao) are used as an ingredient forchocolate.Kola nuts (genusCola) are notable for their highcaffeine content and were commonly used in the past in preparation of variouscola drinks. They are still in use as a stimulant, particularly inWest Africa where they are chewed for this effect.[4] Other well-known members of Malvales in the APG II sense aredaphnes,hibiscus,hollyhocks,okra,jute,baobab trees,cotton, kapok (which mostly comes fromCeiba pentandra, but also from other "Kapok trees" also of Malvales, such asBombax ceiba), anddurian.
Themorphology of Malvales is diverse, with few common characteristics. Among those most commonly encountered areleaf shapes inpalmate form,sepals which areconnate, and a specific structure and chemical composition of the seeds. Thecortex is often fibrous, built of softphloem layers.
Early classifications such as that ofDahlgren placed the Malvales in thesuperorder Malviflorae (also called Malvanae). 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 theThorne system, by theAngiosperm Phylogeny Group, and in the most recent comprehensive treatment of vascular plant families and genera, theKubitzki system.[5]
The dominant family in theAPG II-system is the extended Malvaceae (Malvaceaesensu lato) with over 4225 species, followed by Thymelaeaceae with 898 species. This expanded circumscription ofMalvaceae is taken to include the familiesBombacaceae,Sterculiaceae andTiliaceae. Under the olderCronquist system the order contained these four "core Malvales" families plus theElaeocarpaceae and was placed among theDilleniidae. Some of the currently included families were placed by Cronquist in theViolales.
^Bayer, C. and K. Kubitzki. 2003. Malvaceae, pp. 225–311. In K. Kubitzki (ed.),The Families and Genera of Vascular Plants, vol. 5, Malvales, Capparales and non-betalain Caryophyllales.
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 Botany85, 876–887. (Available online:AbstractArchived 2010-06-26 at theWayback Machine)
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 (2002).Plant Systematics: A Phylogenetic Approach, 2nd edition. pp. 405–410 (Malvales). Sinauer Associates, Sunderland, Massachusetts.ISBN0-87893-403-0.
Kubitzki, K. and M. W. Chase. 2003. Introduction to Malvales, pp. 12– 16. In K. Kubitzki (ed.),The Families and Genera of Vascular Plants, vol. 5, Malvales, Capparales and non-betalain Caryophyllales.
du Mortier, B. C. J. (1829).Analyse des Familles de Plantes, avec l'indication des principaux genres qui s'y rattachent, p. 43. Imprimerie de J. Casterman, Tournay.
Whitlock, B. A. (October 2001). Malvales (Mallow). In:Nature Encyclopedia of Life Sciences. Nature Publishing Group, London. (Available online:DOI |ELS site)
