The families of flowering plants

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L. Watson and M. J. Dallwitz

Malvaceae Juss.

Including Hibiscaceae J.G. Agardh, Philippodendraceae Endl., Plagiantheae (Plagianthaceae) J.G. Agardh; excluding Bombacaceae, Byttneriaceae, Sterculiaceae, Tiliaceae.

Habit and leaf form. Herbs and shrubs, or trees (a few). Mostly ‘normal’ plants, or switch-plants (Lawrencia helmsii); the halophytic L. helmsii ‘cactoid’ (at least, having cactoid lateral branches). Variously mesophytic, or xerophytic. Leaves alternate; spiral; petiolate; non-sheathing; simple. Lamina dissected (usually), or entire; when dissected, palmatifid; palmately veined; cross-venulate. Leaves usually stipulate; leaf development not ‘graminaceous’.

Leaf anatomy. The leaf lamina dorsiventral (usually), or bifacial to centric (rarely). Hydathodes present (occasionally), or absent. Mucilaginous epidermis present (commonly, sometimes penetrating into the mesophyll), or absent. Stomata present; commonly on both surfaces; anomocytic. Hairs of numerous kinds present (in the family: see illustration); eglandular, or eglandular and glandular. Complex hairs commonly present; stellate (very commonly, or shaggy), or peltate. Adaxial hypodermis present, or absent. Lamina with secretory cavities, or without secretory cavities. The mesophyll containing mucilage cells (commonly), or not containing mucilage cells; with sclerenchymatous idioblasts, or without sclerenchymatous idioblasts; usually containing calcium oxalate crystals. The mesophyll crystals mostly druses. Minor leaf veins without phloem transfer cells (4 genera).

Axial (stem, wood) anatomy. Young stems with solid internodes. Pith homogeneous (being usually of thin-walled parenchyma, sometimes sclerenchymatous adjoining the xylem). Secretory cavities present (usually, in cortex and pith), or absent; when present, with mucilage (usually exhibiting mucilage cells). Cork cambium present; initially superficial. Nodes tri-lacunar, or penta-lacunar, or multilacunar. Primary vascular tissue in a cylinder, without separate bundles (usually), or comprising a ring of bundles (when initially traversed by broad rays); collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles present (e.g., in Abutilon), or absent. Secondary thickening developing from a conventional cambial ring.

The wood ring porous, or semi-ring porous, or diffuse porous. The vessels extremely small to medium; solitary, or radially paired, or in radial multiples, or clustered, or in tangential arcs. The vessel end-walls simple. The vessels without vestured pits; with spiral thickening, or without spiral thickening. The axial xylem with tracheids, or without tracheids (?); without vasicentric tracheids; with fibre tracheids, or without fibre tracheids; with libriform fibres, or without libriform fibres; without septate fibres. The fibres without spiral thickening. The parenchyma apotracheal, or paratracheal. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones. ‘Included’ phloem absent. Tile cells present (Durio and Pterospermum types). The wood partially storied (nearly always, VP or VPR), or not storied (“only in very small stems”). Tyloses present (rarely), or absent.

Reproductive type, pollination. Plants hermaphrodite (usually), or dioecious (rarely), or polygamomonoecious (rarely). Floral nectaries present (these trichomatic). Pollination entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in cymes. The ultimate inflorescence units cymose. Inflorescences compound cymose, composed of cincinni. Flowers small to large; regular to somewhat irregular. The floral irregularity involving the perianth (the petals often asymmetrical), or involving the perianth and involving the androecium. Flowers cyclic. Free hypanthium absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous, or gamosepalous (basally); regular; valvate. Epicalyx present (often, representing aggregated bracteoles or stipules?), or absent. Corolla 5; 1 whorled; polypetalous (but often seeming gamopetalous at first sight, through association with the androecial tube); contorted, or imbricate; often asymmetrical.

Androecium (5–)15–100 (i.e., usually ‘many’). Androecial members branched (usually, involving the inner whorl of stamens, the androecium originating from relatively few trunk bundles); when many (i.e. usually), maturing centrifugally; adnate (to the petals); coherent (the filaments forming a tube); 1 adelphous (the tube attached to the petals); 1 whorled (usually, the outer whorl being supposedly absent). Androecium exclusively of fertile stamens (or rather, half-stamens, each having only a half anther). Stamens (5–)15–50; isomerous with the perianth to polystemonous. Anthers dehiscing via longitudinal slits; introrse; unilocular; bisporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or decussate. Anther wall initially with one middle layer; of the ‘dicot’ type. Tapetum amoeboid. Pollen polysiphonous; shed as single grains. Pollen grains aperturate; 3–4 aperturate, or 5–100 aperturate (or more, in Althea); colporate, or foraminate, or rugate; usually spinulose; 2-celled (in 5 genera).

Gynoecium (1–)5(–100) carpelled (i.e. sometimes ‘many). The pistil 1–5(–100) celled (— occasionally ‘many’). Gynoecium syncarpous; synovarious to synstylovarious; superior. Ovary (1–)5(–100) locular (occasionally many-locular). Locules secondarily divided by ‘false septa’ (in Malopeae only, these horizontal, resulting in one-ovuled segments), or without ‘false septa’ (usually); in Malopeae each divided horizontally into one-ovulate locelli, or not horizontally divided (usually). Styles (1–)5(–20); free to partially joined; apical. Stigmas dry type; papillate, or non-papillate; Group II type. Placentation axile. Ovules 1–50 per locule (i.e. to ‘many’); ascending (usually), or pendulous (sometimes); with ventral raphe to with dorsal raphe; anatropous to campylotropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; proliferating (often, forming up to 20 cells), or not proliferating (often); ephemeral, or persistent. Synergids pear-shaped, or hooked (sometimes with filiform apparatus). Endosperm formation nuclear. Embryogeny asterad.

Fruit non-fleshy (usually), or fleshy; dehiscent, or indehiscent, or a schizocarp. Mericarps when schizocarpic, (1–)5(–100); comprising follicles, or comprising nutlets. Fruit a capsule (usually), or a berry (Malvaviscus). Capsules loculicidal. Seeds endospermic. Endosperm oily. Seeds conspicuously hairy, or not conspicuously hairy. Cotyledons 2. Embryo chlorophyllous (7/9), or achlorophyllous (2/2); usually curved. Micropyle zigzag.

Seedling. Germination phanerocotylar.

Physiology, phytochemistry. C3. C3 physiology recorded directly in Abutilon, Gossypium, Malva, Sida, Sphaeralcea. Anatomy non-C4 type (Gossypium, Hibiscus, Malva, Sphaeralcea, Thespesia). Sugars transported as sucrose (Abutilon, Hibiscus, Montezuma). Cyanogenic, or not cyanogenic. Alkaloids present (?), or absent (mostly). Iridoids not detected. Saponins/sapogenins absent. 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). Aluminium accumulation not found. Sieve-tube plastids S-type.

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.

General remarks. Bayer et al. (1999) expanded Malvaceae to include Bombacaceae, Sterculiaceae and Tiliaceae, consequent on a combined analysis of plastid atpB and rbcL DNA sequences. Comparisons of this attempted compilation of data for Malvaceae sensu stricto with descriptions of the segregate families (q.v.) offer reasonable grounds in terms of character correlations for retaining them.

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.

Illustrations. • Technical details: Malva, Lavatera. • Technical details: Althaea, Plagianthus. • Technical details: Abutilon, Malva (Lindley). • Althaea hirsuta and Althaea officinalis: Eng. Bot. 277–278, 1864. • Alyogyne hakeifolia: as Hibiscus lilacinus, Bot. Reg. 2009, 1837. • Alyogyne huegelii: as Hibiscus wragae, Bot. Reg. xxvi, 69 (1840). • Hibiscus hybrid, 'cameroni-fulgens': Bot. Reg. 1844, 28. • Hibiscus rosasinensis: Bot. Reg. 1826, 1836. • Lavatera arborea: Eng. Bot. 279, 1864. • Malva moschata and Malva sylvestris: Eng. Bot. 280–281, 1864. • Malva moschata. • Malva sylvestris. • Palaua rhombifolia: as Palavia, Bot. Reg. 1375, 1830. • Leaf hairs of Althaea, Malachra and Malvastrum, with Durio (Bombacaceae): Solereder, 1908).

Quotations

GONZALO: Had I plantation of this isle, my lord —
ANTONIO: He’d sow’t with nettle-seed.
SEBASTIAN: Or docks or mallows.
(‘Tempest’ ii, 1 — Malva sylvestris being notoriously untidy)


This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG).

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2013. http://delta-intkey.com’.

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