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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

MALVACEAE MALLOW FAMILY

Steven R. Hill, except as noted


Annual to tree; generally with stellate hairs, often with bristles or peltate scales; juice generally mucilage-like; bark fibrous. Leaf: generally cauline, alternate, petioled, simple [palmate-compound], generally palmate-lobed and/or veined, generally toothed, evergreen or not; stipules persistent or not. Inflorescence: head, spike, raceme, or panicle, in panicle or not (a compound panicle), or flowers >= 1 in leaf axils, or flowers generally 1 opposite a leaf or on a spur; bracts leaf-like or not; bractlets 0 or on flowering stalks, often closely subtending calyx, generally in involucel. Flower: generally bisexual, radial; sepals 5, generally fused at base, abutting in bud, larger in fruit or not, nectaries as tufts of glandular hairs at base; petals (0)5, free from each other but generally fused at base to, falling with filament tube, clawed or not; stamens 5–many, filaments fused for most of length into tube around style, staminodes 5, alternate stamens, or generally 0; pistil 1, ovary superior, stalked or generally not, chambers generally >= 5, styles or style branches, stigmas generally 1 or 1–2 × chamber number. Fruit: loculicidal capsule, [berry], or 5–many, disk- or wedge-shaped segments (= mericarps).
266 genera, 4025 species: worldwide, especially warm regions; some cultivated (e.g., Abelmoschus okra; Alcea hollyhock; Gossypium cotton; Hibiscus hibiscus). [Angiosperm Phylogeny Group 1998 Ann Missouri Bot Gard 85:531–553] Recently treated to include Bombacaceae, Sterculiaceae, Tiliaceae. Mature fruit needed for identification; "outer edges" are surfaces between sides and back (abaxial surface) of segment. "Flower stalk" used instead of "pedicel", "peduncle", especially where both needed (i.e., when flowers both 1 in leaf axils and otherwise). —Scientific Editors: Steven R. Hill, Thomas J. Rosatti.
Unabridged references: [Alverson et al. 1999 Amer J Bot 86:1474–1486; Bayer et al. 1999 Bot J Linn Soc 129:267–303; Hill 2009 Madroño 56:104–111]

Key to Malvaceae

1. Flower generally < 3 mm wide; petals with thread-like claws; ovary, fruit stalked ..... AYENIA

1' Flower generally > 3 mm wide; petals 0 or without thread-like claws; ovary, fruit not stalked

2. Petals 0; calyx showy, generally > 25 mm wide; flowers 1 in leaf axils; shrub, small tree ..... FREMONTODENDRON

2' Petals 5, often showy; calyx not showy, generally < 25 mm wide; flowers 1 in leaf axils or not; annual, perennial herb, to small tree

3. Fruit a capsule; seeds 2–many per chamber; flowers showy, generally 1 in leaf axils or on axillary short-shoots

4. Fruit chambers 3–5; style not branched, generally shallowly lobed at tip; involucel 3(5)-lobed, leaf-like, generally persistent; seeds obovoid or angular, generally long-white-hairy; fruit generally gland-dotted ..... [Gossypium hirsutum]

4' Fruit chambers 5; style branched or deeply lobed at tip; involucel 3–12-lobed, not leaf-like, shed in age or not; seeds reniform, short-hairy or glabrous; fruit not gland-dotted

5. Style 5-branched at tip; petals generally white, yellow, lavender, or red; involucel 5–12(20)-lobed, persistent ..... HIBISCUS

5' Style 5-lobed at tip; petals white, pink, blue, or purple; involucel 3–6-lobed, persistent or not

6. Perennial herb to shrub; petals generally white, yellow, blue, or lilac-blue to purple, membranous; involucel lobes 6, linear, persistent ..... [Alyogyne huegelii]

6' Small tree; petals white to rose-pink, fleshy; involucel lobes 3–5, generally ovate, generally deciduous ..... LAGUNARIA

3' Fruit of 5–40 segments that generally separate from axis and each other when mature; seeds generally 1–4(15) per chamber; flowers showy or not, 1–10 in leaf axils or > 1 in spike, raceme, or panicle

7. Stigmas linear, on inner side of style branches; fruit segments indehiscent

8. Anthers near top of filament tube, in 2 concentric series; bractlets subtending calyx 0(1–3), generally not forming involucel; fruit segments 5–10, beak short or 0 ..... SIDALCEA

8' Anthers near top of filament tube, below, not in 2 series; bractlets subtending calyx 3–11, generally forming involucel; fruit segments 5–40, beak 0

9. Bractlets 5–11, fused; flowers generally > 6 cm wide, in (spike-) or raceme-like cymes; petal veins generally indistinct; stem erect ..... ALCEA

9' Bractlets 3, free or ± fused; flowers generally < 6 cm wide, 1–10 in leaf axils, generally not in spike- or raceme-like cymes (occasionally in raceme-like cymes in Malva); petal veins often distinct; stem prostrate to erect

10. Fruit segments generally lacking edges, seed generally not firmly enclosed by, readily separating from fruit wall; bractlets fused ± 1/2 ..... LAVATERA

10' Fruit segments generally with edges, seed firmly enclosed by, not readily separating from fruit wall; bractlets free or fused ± 1/2 ..... MALVA

7' Stigmas head-like or obliquely squared, at tip of style branches; fruit segments indehiscent or ± dehiscent

11. Fruit segment below indehiscent, firm, net-veined, above dehiscent, with 2 spreading, scarious wings; bractlets 0; shrub; Peninsular Ranges, Sonoran Desert ..... HORSFORDIA

11' Fruit segment indehiscent or not, net-veined or not, wings 0; bractlets 0–3; annual to shrub; widespread including e Peninsular Ranges, Sonoran Desert

12. Fruit segment generally 1–6(15)-seeded

13. Petals salmon-orange; fruit segment 2-chambered, 2-seeded; flowers 1 in leaf axils; bractlets 3, ± persistent; stem decumbent to prostrate, rooting ..... MODIOLA

13' Petals occasionally salmon-orange; fruit segment 1–±2-chambered, 1–6(15)-seeded; flowers 1 in leaf axils, or in cyme, raceme, or panicle; bractlets 0–3, persistent or not; stem erect or prostrate, generally not rooting

14. Petals generally pale yellow, orange, white, pink, or ± red; bractlets 0; seeds 3–9(15) per fruit segment

15. Stem generally erect (decumbent); petals yellow, yellow-orange, orange-pink, or ± red; fruit segment not inflated, 3–6(15)-seeded, walls firm to woody ..... ABUTILON

15' Stem generally decumbent or trailing; petals white to pale yellow; fruit segment inflated, 3-seeded, walls flexible, papery ..... HERISSANTIA

14' Petals white, ± rose, pink, ± lavender, or red-orange; bractlets generally 1–3; seeds 1–3(4) per fruit segment

16. Fruit segment bristly, ± dehiscent to base, generally not net-veined; bractlets 3, ± persistent; stigmas generally oblique-squared, often ± elongate; North Coast, High North Coast Ranges, Cascade Range, Modoc Plateau (Shasta Co.), Klamath Ranges ..... ILIAMNA

16' Fruit segment generally not bristly, below indehiscent, strongly net-veined, above dehiscent, smooth; bractlets (0)1–3, generally deciduous; stigmas generally symmetric, head-like; especially Desert or disturbed areas ..... SPHAERALCEA (3)

16'a. Bractlets 3, conspicuous, persistent; petals dark-veined at base; generally disturbed urban sites ..... [Anisodontea capensis] (2)

16'a' Bractlets (0)1–3, inconspicuous, generally deciduous; petals not dark-veined; generally Desert ..... SPHAERALCEA (3)

12' Fruit segment generally 1-seeded

17. Bractlets 0

18. Generally subshrub (annual); fruit segment below indehiscent, strongly net-veined, above dehiscent, smooth; native, especially Desert ..... SPHAERALCEA (3)

18' Generally annual (perennial herb); fruit segment ± uniform; naturalized, widespread, including D

19. Petals ± purple, white, or yellow; leaves generally ± lobed to hastate; fruit segment side walls disintegrating ..... ANODA

19' Petals pale- to orange-yellow; leaves unlobed; fruit segment side walls not disintegrating ..... [Sida rhombifolia]

17' Bractlets generally 1–3, occasionally deciduous in flower or fruit

20. Fruit segment dehiscent; flowers generally > 1 in leaf axils; widespread, generally chaparral ..... MALACOTHAMNUS

20' Fruit segment partly or fully indehiscent; flowers 1 in leaf axils or in generally raceme-like cymes; generally Desert or disturbed sites

21. Fruit segment below indehiscent, sides strongly net-veined, above dehiscent, sides smooth; petals generally rose-pink to salmon-orange; inflorescence raceme-like, generally in panicle, flowers facing out ..... SPHAERALCEA (3)

21a. Bractlets 3, conspicuous, persistent; petals dark-veined at base; generally disturbed urban sites ..... [Anisodontea capensis] (2)

21a' Bractlets (0)3, inconspicuous, generally deciduous; petals not dark-veined; generally Desert ..... SPHAERALCEA (3)

21' Fruit segment generally indehiscent, sides generally ± weakly net-veined; petals generally white, pale ± yellow, or ± purple; inflorescence raceme or flowers generally 1 in leaf axils, facing up

22. Annual, prostrate to erect, not weedy, green, glabrous or generally sparsely stellate-hairy; leaf base symmetric; petals white to ± purple ..... EREMALCHE

22' Perennial herb, generally prostrate, generally weedy, ± gray, densely stellate-canescent or hairs scaly; leaf base asymmetric; petals generally pale ± yellow ..... MALVELLA

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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