Sanjeet Kumar
The Malvaceae, or the mallows, are a family of flowering plants containing about 200 genera with close to 2,300 species. Malvaceae is known as the mallow family in English; as les Malvacées in French; as Malvengewächse in German; as Le Malvacee in Italian; as Kaasjeskruidfamilie in Dutch; as Malvaväxter in Swedish; as Katost-familien in Danish, as Kattostfamilien in Norwegian; as Malvakasvit in Finnish, as kassinaerilised in Estonian; as Mályvafélék in Hungarian; and as Slazowate in Polish. Tiliaceae is known as the lime family in England, as les Tiliacées in French; and Lindengewächse in German; as lehmuskasvit in Finnish; as pärnalised in Estonian; and as Hársfafélék in Hungarian.. Bombacaceae is known as Wollbaumgewächse in German. Well-known members of this family include okra, cotton and cacao. The largest genera in terms of number of species include Hibiscus (300 species), Sterculia (250 species), Dombeya (225 species), Pavonia (200 species) and Sida (200 species).
Taxonomy and nomenclature
The circumscription of the Malvaceae is very controversial. The traditional Malvaceae sensu stricto comprise a very homogeneous and cladistically monophyletic group. Another major circumscription, Malvaceae sensu lato, has been more recently defined on the basis that molecular techniques have shown the commonly recognised families Bombacaceae, Tiliaceae, and Sterculiaceae, which have always been considered closely allied to Malvaceae are not monophyletic groups. Thus, the Malvaceae can be expanded to include all of these families so as to compose a monophyletic group. Adopting this circumscription, the Malvaceae incorporate a much larger number of genera.
This article is based on the second circumscription, as presented by the Angiosperm Phylogeny Website. The Malvaceae s.l. (hereafter simply "Malvaceae") comprises nine subfamilies. A tentative cladogram of the family is shown below. The diamond denotes a poorly supported branching (<80%).
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It is important to point out the relationships between these subfamilies are still either poorly supported or almost completely obscure, so the circumscription of the family may change dramatically as new studies are published.
If looking for information about the traditional Malvaceae s.s., we recommend referring to Malvoideae, the subfamily that approximately corresponds to that group.
The English common name 'mallow' (also applied to other members of Malvaceae) comes from Latin malva (also the source for the English word "mauve"). Malva itself was ultimately derived from the word for the plant in ancient Mediterranean languages.[3] Cognates of the word include Ancient Greek μαλάχη (malákhē) or μολόχη (molókhē), Modern Greek μολόχα (molóha), modern Arabic: ملوخية (mulukhiyah) and modern Hebrew: מלוחיה (molokhia).[3][4]
Description
The Malvaceae are herbs, shrubs, or trees. Leaves are generally alternate, often palmately lobed or compound and palmately veined. The margin may be entire, but when dentate, a vein ends at the tip of each tooth (malvoid teeth). Hydathodes present (occasionally), or absent. Mucilaginous epidermis present (commonly, sometimes penetrating into the mesophyll), or absent. Stomata present; commonly on both surfaces; anomocytic. Hairs present; eglandular, or eglandular and glandular Stipules are present. The stems contain mucous canals and often also mucous cavities. Hairs are common, and are most typically stellate. Secretory cavities present (usually, in cortex and pith), or absent; with mucilage (usually accompanied by mucilage cells). Cork cambium present; initially superficial. Nodes tri-lacunar, or penta-lacunar, or multilacunar. Cortical bundles absent. Medullary bundles present (Abutilon), or absent. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones. Xylem with fibre tracheids, or without fibre tracheids; with libriform fibres, or without libriform fibres; with vessels. Vessel end-walls simple. Vessels without vestured pits. Tile cells present (Durio and Pterospermum types). Wood partially storied (VP, VPR); parenchyma apotracheal, or paratracheal. Sieve-tube plastids S-type. The flowers are commonly borne in definite or indefinite axillary inflorescences, which are often reduced to a single flower, but may also be cauliflorous, oppositifolious, or terminal. They often bear supernumerary bracts. They can be unisexual or bisexual, and are generally actinomorphic, often associated with conspicuous bracts, forming an epicalyx. They generally have five valvate sepals, most frequently basally connate, with five imbricate petals. The stamens are five to numerous, and connate at least at their bases, but often forming a tube around the pistils. The pistils are composed of two to many connate carpels. The ovary is superior, with axial placentation, with capitate or lobed stigma. The flowers have nectaries made of many tightly packed glandular hairs, usually positioned on the sepals. The fruit is a loculicidal capsule, schizocarp, berry, or samara
Physiology, biochemistry. Cyanogenic, or not cyanogenic. Alkaloids present (?), or absent (mostly). Iridoids not detected. Proanthocyanidins present, or absent; cyanidin (usually), or cyanidin and delphinidin. Flavonols present, or absent; kaempferol, or quercetin, or kaempferol and quercetin. Ellagic acid absent (11 species, 10 genera). Saponins/sapogenins absent. Aluminium accumulation not found. Sugars transported as sucrose (Abutilon, Hibiscus, Montezuma). C3. C3 physiology recorded directly in Abutilon, Gossypium, Malva, Sida, Sphaeralcea. Anatomy non-C4 type (Gossypium, Hibiscus, Malva, Sphaeralcea, Thespesia).
Geography, cytology. Frigid zone to tropical. Cosmopolitan tropical and temperate, also Iceland. X = 6–17(+), 20(+).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Malviflorae; Malvales. Cronquist’s Subclass Dilleniidae; Malvales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Malvales.
Species 1000. Genera about 100; Abelmoschus, Abutilon, Abutilothamnus, Acaulimalva, Alcea, Allosidastrum, Allowissadula, Althaea, Alyogyne, Anisodontea, Anoda, Anotea, Asterotrichion, Bakeridesia, Bastardia, Bastardiastrum, Bastardiopsis, Batesimalva, Billieturnera, Briquetia, Callirhoe, Calyculogigas, Calyptraemalva, Cenocentrum, Cephalohibiscus, Cienfuegosia, Codonochlamys, Corynabutilon, Cristaria, Decaschistia, Dendrosida, Dicellostyles, Dirhamphis, Eremalche, Fioria, Fryxellia, Gaya, Goethea, Gossypioides, Gossypium, Gynatrix, Hampea, Helicteropsis, Herissantia, Hibiscadelphus, Hibiscus, Hochreutinera, Hoheria, Horsfordia, Howittia, Humbertianthus, Humbertiella, Iliamna, Julostylis, Jumelleanthus, Kearnemalvastrum, Kitaibela, Kokia, Kosteletzkya, Krapovickasia, Kydia, Lagunaria, Lavatera, Lawrencia, Lebronnecia, Lecanophora, Lopimia, Macrostelia, Malachra, Malacothamnus, Malope, Malva, Malvastrum, Malviscus, Malvella, Megistostegium, Meximalva, Modiola, Modiolastrum, Monteiroa, Napaea, Nayariophyton, Neobaclea, Neobrittonia, Nototriche, Palaua, Pavonia, Peltaea, Periptera, Perrierophytum, Phragmocarpidium, Phymosia, Plagianthus, Radyera, Rhynchosida, Robinsonella, Rojasimalva, Senra, Sida, Sidalcea, Sidastrum, Sphaeralcea, Symphyochlamys, Tarasa, Tetrasida, Thespesia, Urena, Urocarpidium, Wercklea, Wissadula.
Economic uses, etc. Gossypium seed supplies commercial cotton, pulp and oil. ‘Rosella fruit’ (Jamaica sorrel) is the fleshy calyx and bracts of Hibiscus sabdariffa, while ‘ochra’ (‘okra’) is the young fruits of Hibiscus esculentus. Some pot-herbs (Malva parviflora), and many ornamentals.
Molecular studies have shown that the members of the Bombacaceae, Malvaceae, Sterculiaceae, and Tiliaceae form a very well-defined monophyletic group that is divided into ten also rather well-defined clades, only two of which correspond to the traditional families Bombacaceae and Malvaceae. Some of the remaining groups are included entirely within either of the remaining families but others cut across the traditional divide between the Sterculiaceae and Tiliaceae. A majority of authors, most notably Bayer and Kubitzki (Fam. Gen. Vasc. Pl. 5: 225-311. 2003), has favored including everything within a greatly enlarged Malvaceae, and treating the individual clades as subfamilies. The alternative view is that the individual clades should be treated as a series of ten families: Bombacaceae (Bombacoideae), Brownlowiaceae (Brownlowioideae), Byttneriaceae (Byttnerioideae), Durionaceae (Durionoideae), Helicteraceae (Helicteroideae), Malvaceae (Malvoideae), Pentapetaceae (Dombeyoideae), Sparrmanniaceae (Grewioideae), Sterculiaceae (Sterculioideae), and Tiliaceae (Tilioideae) (Cheek in Heywood et al., Fl. Pl. Fam. World. 201-202. 2007). For the present treatment, we prefer to retain the familiar, traditional four families, so as to maintain continuity with the treatments in FRPS, and to await a consensus on the two alternative strategies for dealing with the very widely accepted clades. The traditional Malvaceae coincides exactly with one of the major clades. The only possible problem is the relationship with the Bombacaceae, which also has primarily 1-loculed anthers, and some authorities have suggested that the Bombacaceae should be included within the Malvaceae. 
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