Herbs, subshrubs, shrubs, or trees, erect or procumbent, often stellate-hairy, sometimes with glandular-hairs, generally mucilaginous, inner bark tough-fibrous. Leaves usually cauline, alternate, also distichous in Krapovickasia, Malvella, Meximalva, and some species of Sida, subsessile or sessile in some Herissantia, Horsfordia, Sida, Sidastrum, and Sphaeralcea; blade usually symmetric, asymmetric in Malvella, sometimes asymmetric in Pavonia, usually unlobed, sometimes palmately lobed or dissected, margins serrate or entire, primary-veins often palmate (except in Lagunaria), without nectaries (except in Gossypium, Hibiscus, Talipariti, Thespesia, and Urena). Inflorescences terminal or axillary, umbels, spikes, racemes, or panicles or solitary flowers; bracts usually present. Flowers bisexual or unisexual, some species with staminate or pistillate flowers, plants usually hermaphroditic, some dioecious, some monoecious; involucel (epicalyx) present or absent; sepals usually persistent (deciduous in Abelmoschus), 5, ± connate; petals 5, usually distinct, adnate to staminal column and connate to each other at base, falling together, without clawlike appendage; androgynophore absent; androecium monadelphous, in more than 1 concentric series in Sidalcea, staminal column sometimes toothed at apex, stamens 5–many, filaments connate; anthers 1-thecate; staminodes absent or 5 teeth at apex of staminal column; gynoecium syncarpous, ovary superior, 3–40-carpellate; styles 1, branched or unbranched; stigmas truncate, capitate, linear, or filiform, 1–2 times number of carpels. Fruits usually schizocarps with 5–many wedge-shaped mericarps or folliclelike segments, or capsules with 3–5 cells, rarely berries (in Malvaviscus), carpels sometimes with internal protrusion dividing carpel into 2 cells, dehiscence loculicidal, rarely indehiscent. Seeds 2–30, often reniform, glabrous or hairy.

Distribution

Nearly worldwide, mostly in tropical areas

Discussion

Some ornamental malvaceous trees have been introduced to California, none of which is known in the flora area outside of cultivation. These include the Mexican Robinsonella cordata Rose & Baker f. and, from Australia and New Zealand, Hoheria glabrata Sprague, Plagianthus divaricatus J. R. Forster & G. Forster, and P. regius (Poiteau) Hochreutiner. Malope trifida Cavanilles from the Mediterranean region, and the subshrubs Alyogyne Alefeld from Australia, species of Anisodontea C. Presl from South Africa, and Lavatera species from the Mediterranean are sometimes grown as ornamentals; they are not naturalized in the flora area.

Genera ca. 110, species ca. 1800 (42 genera, 220 species in the flora).

Selected References

None.

Lower Taxa

Abelmoschus, Abutilon, Alcea, Allowissadula, Althaea, Anoda, Bastardia, Batesimalva, Billieturnera, Callirhoë, Cienfuegosia, Eremalche, Fryxellia, Gossypium, Herissantia, Hibiscus, Horsfordia, Iliamna, Kosteletzkya, Krapovickasia, Lagunaria, Lavatera, Malachra, Malacothamnus, Malva, Malvastrum, Malvaviscus, Malvella, Meximalva, Modiola, Napaea, Pavonia, Pseudabutilon, Rhynchosida, Sida, Sidalcea, Sidastrum, Sphaeralcea, Talipariti, Thespesia, Urena, Wissadula

Key

1	Involucel usually absent, sometimes present in Callirhoë, Malachra, Malvella, and Sidalcea, often deciduous in Sphaeralcea; fruits schizocarps	> 2
1	Involucel usually present, sometimes absent; fruits schizocarps or capsules	> 23
2	Inflorescences subtended by boat-shaped sessile or subsessile bracts.	Malachra
2	Inflorescences not subtended by boat-shaped sessile or subsessile bracts	> 3
3	Stigmas linear or filiform	> 4
4	Herbs, (1–)2.2(–3) m; inflorescences terminal panicles; flowers unisexual, plants dioecious; corollas white.	Napaea
5	Anthers borne ± evenly along staminal column; staminal columns not comprised of concentric series.	Callirhoë
5	Anthers borne distally on staminal column, staminal columns comprised of concentric inner and outer series of filaments.	Sidalcea
6	Mericarps 1-celled; distally dehiscent, partially dehiscent, or indehiscent; seeds usually 1 per mericarp (3–6 in Abutilon; 2–6 in Herissantia)	> 11
7	Calyces usually shorter than fruits; seeds 1–3 per mericarp	> 9
8	Calyces usually 8–13 mm; mericarps with prominent, medial constriction resulting in 2 cells.	Allowissadula
8	Calyces 4–8 mm; mericarps with obscure medial constriction (except P. umbellatum).	Pseudabutilon
9	Styles 3–6-branched; petals 3–5 mm.	Wissadula
9	Styles 6–12-branched; petals 6–21 mm	> 10
10	Mericarps with medial constriction, distal cell unwinged; seeds 1 per mericarp; Texas.	Batesimalva
10	Mericarps without medial constriction, distal cell apically winged; seeds 2 or 3 per mericarp; Arizona, California.	Horsfordia
11	Calyces completely enclosing fruits or leaves maplelike	> 12
11	Calyces closely subtending, not enclosing fruits (fruits closely invested by calyx tube in Fryxellia); leaves seldom maplelike (Anoda; Sida hermaphrodita)	> 14
12	Corollas white; calyces not completely enclosing fruits; leaves maplelike; east of Mississippi River.	Sida
12	Corollas yellow or white, fading rose; calyces completely enclosing fruits; leaves not maplelike; west of Mississippi River	> 13
13	Corollas white, fading rose; calyces brownish-membranous at maturity; mericarps fragile-walled, unornamented.	Krapovickasia
13	Corollas yellow; calyces green-membranous at maturity; mericarps indurate, laterally reticulate-walled, with horizontal obtuse rostrum.	Rhynchosida
14	Fruits spheric, inflated, not indurate, setose, reflexed.	Herissantia
14	Fruits not both spheric and inflated (can appear somewhat inflated in Fryxellia but not spheric or pendent), usually indurate, hairy, seldom setose, usually erect	> 15
15	Mericarps 3–6-seeded.	Abutilon
15	Mericarps 1-seeded	> 16
16	Leaf blades cuneate at base, otherwise broadly oblanceolate, 0.5–1.5 cm; mericarps 5; usually saline habitats.	Billieturnera
16	Leaf blades variously shaped at base, ovate, reniform, oblong, elliptic, lanceolate, or linear, usually 1.5+ cm; mericarps 5+; seldom saline habitats (except Malvella)	> 17
17	Mericarps: lateral walls evanescent, spur rarely absent.	Anoda
17	Mericarps: lateral walls persistent (firm or indurate), spur usually absent (except Fryxellia)	> 18
18	Plants cespitose; mericarps with dorsal spur and endoglossum.	Fryxellia
19	Corollas yellow or yellowish, usually 6+ mm; calyces 4–10 mm, costate or not; pedicels not capillary	> 21
20	Mericarps 7 or 8, lateral walls prominently reticulate; leaves distichous; styles 7 or 8, purple; corollas rotate; inflorescences solitary flowers.	Meximalva
20	Mericarps 5, lateral walls smooth or weakly reticulate; leaves not distichous; styles 5, pallid; corollas reflexed; inflorescences terminal panicles.	Sidastrum
21	Leaf blades asymmetric; stems prostrate; indument sometimes ± lepidote; often saline habitats.	Malvella
21	Leaf blades symmetric; stems usually erect, seldom prostrate; indument never lepidote; not saline habitats	> 22
22	Herbage prominently viscid; calyces divided nearly to base, not costate; fruit walls papery.	Bastardia
22	Herbage seldom viscid; calyces usually 1/2-divided, usually costate; fruit walls indurate.	Sida
23	Ovaries 3–5-carpellate; fruits usually capsules	> 24
23	Ovaries (5)6–36-carpellate; fruits schizocarps	> 34
24	Trees; leaves: venation pinnate; involucellar bractlets basally connate.	Lagunaria
24	Trees, subshrubs, or herbs; leaves: venation palmate; involucellar bractlets usually distinct (except Abelmoschus, Talipariti, and Urena), not enclosing bud	> 25
25	Involucellar bractlets 3, distinct	> 26
25	Involucellar bractlets 4+, distinct or ± connate	> 27
26	Capsules ovoid or subglobose to oblong, dehiscent; shrubs or trees.	Gossypium
26	Capsules oblate, indehiscent; trees.	Thespesia
27	Calyces deciduous, spathaceous.	Abelmoschus
27	Calyces persistent, not spathaceous	> 28
28	Fruits ovoid, subglobose, or spheroid, not fleshy; seeds 2–20 per locule	> 29
28	Fruits oblate, rarely fleshy, seeds 1 per locule	> 31
29	Calyces gland-dotted; ovaries 3–5-carpellate; styles usually connate to apex; stigmas 3–5, decurrent.	Cienfuegosia
29	Calyces not gland-dotted; ovaries 5-carpellate; styles proximally connate, distally 5-fid; stigmas 5, capitate to discoid	> 30
30	Stipules persistent or caducous, not enlarged in bud; relatively dry habitats or freshwater swamps.	Hibiscus
30	Stipules caducous, enlarged in bud, leaving annular scars; estuarine habitats.	Talipariti
31	Fruits 5-angled, sections dehiscent; foliage scabrid; styles 5-fid.	Kosteletzkya
31	Fruits not angled, indehiscent; foliage glabrous or hairy, seldom scabrid; styles 10-fid	> 32
32	Leaves with abaxial nectaries; involucellar bractlets 5.	Urena
32	Leaves without nectaries; involucellar bractlets 5–9	> 33
33	Petals basally auriculate, usually red; fruits fleshy, red; stamens and stigmas usually exserted.	Malvaviscus
33	Petals usually not auriculate, lavender, pink, or yellow; fruits dry, not colored; stamens and stigmas usually included.	Pavonia
34	Involucellar bractlets 6–12	> 35
34	Involucellar bractlets (0 or)1–3	> 36
35	Petals 3+ cm; mericarps 2-celled, proximal cell fertile, distal cell sterile; staminal columns 5-angled, anthers pale yellow.	Alcea
35	Petals (0.9–)1–2 cm; mericarps 1-celled; staminal columns cylindric, anthers purple or pale pink to almost white or yellow.	Althaea
36	Leaf blades asymmetric; herbage hairy, hairs mixed stellate and lepidote.	Malvella
36	Leaf blades symmetric; herbage usually stellate-hairy, glabrate, or glabrous, sometimes some hairs simple, seldom lepidote	> 37
37	Mericarps 2-celled; seeds 2 per mericarp; corollas salmon-orange; mericarps drying black; stems prostrate to ascending.	Modiola
37	Mericarps 1 or 2-celled, seeds 1–4 per mericarp; corollas sometimes salmon-orange; mericarps drying black, brown, or tan; stems usually erect, sometimes ascending, decumbent, or prostrate	> 38
38	Corollas yellow or yellow-orange, without darker veins.	Malvastrum
38	Corollas usually white, pinkish, pink, magenta, rose-purple, rose-pink, purple, mauve, orange, red-orange, or red, sometimes salmon-orange, sometimes with darker veins	> 39
39	Stigmas capitate or obliquely capitate	> 40
39	Stigmas linear or filiform	> 43
40	Stigmas obliquely capitate; mericarps 8–15 mm; seeds 2–4 per mericarp.	Iliamna
40	Stigmas capitate; mericarps to 8 mm; seeds 1–3 per mericarp	> 41
41	Fruits glabrous; mericarps indehiscent; seeds 1 per mericarp; herbs, annual.	Eremalche
41	Fruits hairy; mericarps dehiscent; seeds 1–3 per mericarp; usually shrubs or subshrubs, rarely herbs	> 42
42	Mericarps dehiscent to base, usually smooth; seeds 1 per mericarp; involucellar bractlets persistent, 3.	Malacothamnus
42	Mericarps proximally indehiscent, ± dehiscent apically, reticulate; seeds 1 or 2(or 3) per mericarp; involucellar bractlets persistent or deciduous, 2 or 3.	Sphaeralcea
43	Mericarps obtusely beaked, mucronate, or cuspidate	> 44
43	Mericarps not beaked, mucronate, or cuspidate	> 45
44	Mericarps obtusely beaked or not; anthers ± evenly distributed along staminal column; staminal column single; roots usually taproots; mostly east of 103°W longitude.	Callirhoë
44	Mericarps mucronate or cuspidate; anthers distal on staminal column; staminal column double (concentric inner and outer series of filaments); roots usually fibrous, fleshy or not; mostly west of 103°W longitude.	Sidalcea
45	Involucellar bractlets present or absent; staminal column double (concentric inner and outer series of filaments).	Sidalcea
45	Involucellar bractlets present; staminal column single	> 46
46	Mericarps elliptic in cross section, edges rounded, walls readily separating from seed; involucellar bractlets basally connate 1/2 length; style base persistent on fruit, swollen.	Lavatera
46	Mericarps wedge-shaped in cross section, edges usually sharp, walls not readily separating from seed; involucellar bractlets usually distinct, sometimes basally connate; style bases not both persistent and swollen.	Malva