MALVACEAE

MALLOW FAMILY

Steven R. Hill, except as specified

Annual, perennial herb, shrubs, trees, generally stellate-hairy; juice sticky; inner bark tough, fibrous
Leaves alternate, simple, petioled; blade generally palmately veined or lobed, stipules present
Inflorescence often leafy; whorl or involucre of bractlets often subtending calyx
Flower generally bisexual, radial; calyx lobes 5, margins abutting in bud; petals 5, free (fused at base to filament tube, so falling together); stamens many, filaments fused into a tube surrounding style, tube fused in turn to petal bases; pistil 1, ovary superior, chambers generally 5 or more, style branches, stigmas generally 1 or 2 X as many as chambers
Fruit of 5–many disk- or wedge-shaped segments, loculicidal capsule, or berry
Genera in family: 100 genera, 2000 species: worldwide, especially warm regions; some cultivated (e.g., Abelmoschus , okra; Alcea ; Gossypium , cotton; Hibiscus , Malvaviscus )
Recent taxonomic note: Recently treated to include Sterculiaceae [Angiosperm phylogeny Group 1998 Ann Missouri Bot Gard 85:531–553; Alverson et al. 1999 Amer J Bot 86:1474–1486; Bayer et al. 1999 Bot J Linn Soc 129:267–303]
Mature fruit important for identification.

MALACOTHAMNUS

BUSH MALLOW

David M. Bates

Subshrubs, shrubs; hairs sparse to dense, stellate (stalked or sessile), simple, and glandular
Stem erect; branches sometimes spreading
Leaf: blade toothed, lobes 0 or 3–7
Inflorescence head-like to panicle-like, composed of axillary clusters (each a cyme) variously arrayed; clusters few–many-flowered, loose to dense, congested or well separated; bractlets subtending calyx 3
Flower: petals > calyx, generally pale pinkish purple or white (often purplish when dry); filament column included; stigmas head-like
Fruit disk-like; segments 7–14, 2–5 mm, separating, each dehiscing into 2 valves, unarmed, smooth, top hairy
Seed 1 per fruit segment
Species in genus: 11 species: CA, nw Mex
Etymology: (Greek: soft shrub)
Spp. represent major morphological variants; they are all interfertile and sometimes intergrade in areas of proximity. Variation between populations (especially in hairs, inflorescence, and flowers) is high and of ± complex pattern within most species

Native

M. fremontii A. Gray

Plant 5–20 dm; hairs ± woolly, white
Stem: branches generally coarse, stiff
Leaf: blade 4–6(11) cm, ovate to wider than long, thin or thick, upper surface hairy, lobes obscurely 5
Inflorescence spike- to panicle-like; clusters many-flowered, sessile to peduncled, generally well separated; bractlets 3–15 mm, generally < 0.5 mm wide
Flower: calyx 5.5–13 mm, not angled in bud, lobes free in bud, 3–10 mm, generally > or >> tube, generally narrowly triangular-acuminate, soft-hairy; petals light purple
Chromosomes: 2n=34
Ecology: Chaparral to pine woodland
Elevation: 60–1300 m (n CA), 450–2300 m (s CA), 1700–2800 m (SNE).
Bioregional distribution: High North Coast Ranges, Inner North Coast Ranges, Sierra Nevada Foothills, Tehachapi Mountain Area, e San Francisco Bay Area, Transverse Ranges, San Jacinto Mountains, East of Sierra Nevada, Desert Mountains (Panamint Mtns)
Flowering time: Apr–Sep
Synonyms: subsp. cercophorus (B.L. Rob.) Munz; M. helleri (Eastw.) Kearney (Heller's bush mallow); M. howellii (Eastw.) Kearney; M. orbiculatus (Greene) Greene
Plants in NCoR with small calyces are the " M. helleri " form; those in SnFrB with large calyces are the " subsp. cercophorus " or " M. howellii " form; both forms also occur elsewhere. s CA plants are generally less woolly (" M. orbiculatus " form), may intergrade with M. fasciculatus
Horticultural information: DRN: 6, 7, 14, 18, 19, 20, 21, 22, 23 &SUN: 15, 16, 17, 24.