Malvaceae

Jussieu
Synonyms: Mallow
Treatment appears in FNA Volume 6. Treatment on page 187. Mentioned on page 188, 189, 194, 197.

Herbs, subshrubs, shrubs, or trees, usually stellate-hairy. Leaves alternate, usually spiral, sometimes distichous (Malvoideae), usually petiolate, sometimes subsessile or sessile (Malvoideae), stipulate (usually well developed), simple (compound in Abelmoschus); blade unlobed or palmately lobed, palmately veined. Inflorescences axillary, terminal, or leaf-opposed. Flowers bisexual or unisexual, usually actinomorphic; involucel (epicalyx) sometimes deciduous (Malvoideae, Sterculioideae), (4–) 5 (–8), distinct or connate; petals 4 or 5 (absent in Bombacoideae and Sterculioideae, rarely absent in Grewioideae); nectaries glandular-hairs on adaxial base of sepals, petals, or androgynophores, sometimes absent; androgynophore present or absent; stamens [4–] 5–100 [–1500], usually in antipetalous groups; usually same number as sepals, distinct or connate, sessile or on androgynophore; ovules (1–) 2–many per ovary. Fruits usually capsules, sometimes follicles, schizocarps, berries, or nuts. Seeds: cotyledons usually folded, endosperm absent or sparse to copious.

Discussion

Genera ca. 240, species ca. 4350 (52 genera, 250 species in the flora).

Malvaceae comprise taxa traditionally separated among four families: Malvaceae, Bombacaceae Kunth, Sterculiaceae Ventenat, and Tiliaceae Jussieu. Morphological characters distinguishing these previously recognized families are notoriously ambiguous and/or absent. Multiple tribes and genera (for example, Fremontodendron) have been transferred between families as taxonomic boundaries changed throughout history. Molecular phylogenies indicate that only one of the four previously recognized families (Malvaceae in the narrow sense) forms a monophyletic group (C. Bayer et al. 1999; W. S. Alverson et al. 1999) and the monophyly of an expanded familial circumscription, including all four previously accepted families, is well documented (W. S. Judd and S. R. Manchester 1997; Alverson et al. 1998; Bayer et al.). Based on morphological, molecular, and biogeographic data, Malvaceae now include nine subfamilies (Bayer et al.; Alverson et al. 1999), six of which are represented in the flora area; Malvoideae and Bombacoideae form a monophyletic group that is part of a larger clade that includes some

traditional components of Tiliaceae and Sterculiaceae (now Tilioideae and Sterculioideae). A second clade contains Grewioideae and Byttneriodeae. Not included in the flora are members of subfamilies Brownlowioideae Burret, Dombeyoideae Beilschmied, and Helicteroideae Meisner.

Malvaceae range widely in inflorescence structure; all members share a basic repeating bicolor unit (a terminal flower and three bracts or an epicalyx; C. Bayer 1999). Floral nectaries in the family are composed of dense multicellular, glandular hairs on sepals, petals, or androgynophore (S. Vogel 2000). These nectaries provide nectar to a broad range of cells in wood; M. M. Chattaway 1933) are restricted to Malvaceae but are not present in every taxon.

Representatives of Malvaceae are present on every continent except Antarctica; diversity increases in warmer regions. A majority of the genera in Malvoideae and Bombacoideae are native to the New World (P. A. Fryxell 1997); members of Byttnerioideae, Grewioideae, and Sterculioideae are more evenly distributed throughout the Tropics. Tilioideae are restricted to the Northern Hemisphere (C. Bayer and K. Kubitzki 2003).

Malvaceae have an extensive pollen fossil record and a majority of the subfamilies are represented in the Paleocene or Eocene. Tilia (Tilioideae) fossil pollen and leaves are present in western North American temperate forests (where it is now absent) from the mid Eocene (S. R. Manchester 1994; H. W. Meyer and Manchester 1997). North American fossil pollen deposits of Bombacoideae are plentiful in the Cretaceous (W. Krutzsch 1989; B. E. Pfeil et al. 2002 and references therein).

The hairy seed coat of cotton [Gossypium (Malvoideae)] is the most economically valuable product in the family and the historical and evolutionary importance of its domestication is well documented. The seeds of cacao [Theobroma cacao (Sterculioideae)] are the basis of chocolate. Okra [Abelmoschus esculentus (Malvoideae)] is a major vegetable crop in the southeastern United States. Tilia (Tilioideae) trees are planted throughout temperate regions to beautify streets and parks. The marshmallow, Althaea officinalis (Malvoideae), is a perennial herb found in northeastern North America and Europe; the mucilage from its roots was used to make the original marshmallow.

Key to Subfamilies of Malvaceae

Illustrations

 Family TaxonIllustrator 
FNA6 P21 Brachychiton populneus.jpegMalvaceae
Malvaceae
Malvaceae
Brachychiton populneus
Firmiana simplex
Fremontodendron californicum
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P22 Tilia americana.jpegMalvaceae
Malvaceae
Malvaceae
Tilia americana
Corchorus siliquosus
Triumfetta rhomboidea
Barbara Alongi
Barbara Alongi
Barbara Alongi
FNA6 P23 Ayenia filiformis.jpegMalvaceae
Malvaceae
Malvaceae
Ayenia filiformis
Hermannia pauciflora
Melochia corchorifolia
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P24 Waltheria detonsa.jpegMalvaceae
Malvaceae
Malvaceae
Waltheria detonsa
Abelmoschus esculentus
Abutilon hypoleucum
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P25 Abutilon mollicomum.jpegMalvaceae
Malvaceae
Malvaceae
Abutilon mollicomum
Abutilon palmeri
Alcea rosea
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P26 Allowissadula holosericea.jpegMalvaceae
Malvaceae
Malvaceae
Allowissadula holosericea
Althaea officinalis
Anoda abutiloides
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P27 Bastardia viscosa.jpegMalvaceae
Malvaceae
Malvaceae
Bastardia viscosa
Batesimalva violacea
Billieturnera helleri
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P28 Callirhoe leiocarpa.jpegMalvaceae
Malvaceae
Malvaceae
Cienfuegosia yucatanensis
Eremalche rotundifolia
Eremalche parryi subsp. parryi
Callirhoe involucrata var. involucrata
Callirhoe leiocarpa
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P29 Fryxellia pygmaea.jpegMalvaceae
Malvaceae
Malvaceae
Fryxellia pygmaea
Gossypium thurberi
Herissantia crispa
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P30 Hibiscus coulteri.jpegMalvaceae
Malvaceae
Malvaceae
Hibiscus coulteri
Hibiscus aculeatus
Hibiscus grandiflorus
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P31 Horsfordia alata.jpegMalvaceae
Malvaceae
Malvaceae
Malvaceae
Horsfordia alata
Horsfordia newberryi
Iliamna rivularis
Kosteletzkya depressa
Linny Heagy
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P32 Krapovickasia physaloides.jpegMalvaceae
Malvaceae
Malvaceae
Krapovickasia physaloides
Lagunaria patersonia
Lavatera thuringiaca
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P33 Malachra capitata.jpegMalvaceae
Malvaceae
Malvaceae
Malachra capitata
Malacothamnus fasciculatus
Malacothamnus palmeri
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P34 Malva assurgentiflora.jpegMalvaceae
Malvaceae
Malvaceae
Malva assurgentiflora
Malva parviflora
Malvastrum coromandelianum
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P35 Malvaviscus arboreus.jpegMalvaceae
Malvaceae
Malvaceae
Malvaceae
Malvaceae
Malvaviscus arboreus var. arboreus
Malvaviscus arboreus var. drummondii
Malvella leprosa
Malvella sagittifolia
Meximalva filipes
Linny Heagy
Linny Heagy
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P36 Modiola caroliniana.jpegMalvaceae
Malvaceae
Malvaceae
Modiola caroliniana
Napaea dioica
Pavonia lasiopetala
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P37 Pseudabutilon thurberi.jpegMalvaceae
Malvaceae
Malvaceae
Pseudabutilon thurberi
Rhynchosida physocalyx
Sida elliottii var. elliottii
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P38 Sida neomexicana.jpegMalvaceae
Malvaceae
Malvaceae
Sida neomexicana
Sida tragiifolia
Sidalcea asprella subsp. asprella
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P39 Sidalcea diploscypha.jpegMalvaceae
Malvaceae
Malvaceae
Sidalcea diploscypha
Sidalcea glaucescens
Sidalcea hickmanii subsp. parishii
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P40 Sidalcea oregana.jpegMalvaceae
Malvaceae
Malvaceae
Sidalcea oregana subsp. spicata
Sidastrum paniculatum
Sphaeralcea angustifolia var. oblongifolia
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P41 Sphaeralcea coccinea.jpegMalvaceae
Malvaceae
Malvaceae
Sphaeralcea coccinea var. coccinea
Sphaeralcea fendleri var. fendleri
Sphaeralcea grossulariifolia
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P42 Talipariti tiliaceum.jpegMalvaceae
Malvaceae
Malvaceae
Talipariti tiliaceum var. pernambucense
Thespesia populnea
Urena lobata
Linny Heagy
Linny Heagy
Linny Heagy
FNA6 P43 Wissadula periplocifolia.jpegMalvaceae
Cochlospermaceae
Cochlospermaceae
Thymelaeaceae
Wissadula periplocifolia
Amoreuxia wrightii
Amoreuxia palmatifida
Dirca palustris
Linny Heagy
Linny Heagy
Linny Heagy
Linny Heagy

Key

Key to Subfamilies of Malvaceae

1 Gynoecium apocarpous; petals absent; epicalyx absent; androgynophore present; flowers functionally unisexual Sterculioideae
1 Gynoecium syncarpous; petals present or absent; epicalyx present or absent; androgynophore present or absent; flowers usually bisexual > 2
2 Petals absent Bombacoideae
2 Petals usually present > 3
3 Epicalyx usually absent > 4
3 Epicalyx usually present, rarely absent > 5
4 Androgynophore absent; nectaries on sepals Tilioideae
4 Androgynophore present or absent; nectaries on petals or androgynophore Grewioideae
5 Staminodes usually present; anthers 2- or 3-thecate Byttnerioideae
5 Staminodes absent or relatively small; anthers 1-thecate Malvoideae