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. fasciculatus (Torr. & A. Gray) Greene

CHAPARRAL MALLOW

Plant 10–50 dm; hairs sparse to dense, white to tawny
Stem: branches generally slender
Leaf: blade 2–6(11) cm, ovate to ± round, generally thin; upper surface generally sparsely hairy; lobes 0–7, angular to rounded, not overlapping (sinuses open)
Inflorescence spike- to openly panicle-like; clusters generally many-flowered, dense and sessile to widely spreading; bractlets 1–8 mm, < 1 mm wide
Flower: calyx 4–11 mm, lobes 1.8–8 mm, ± = tube, triangular to ovate, acute to short-acuminate, densely hairy, 2–3 often joined when flower open
Chromosomes: 2n=34
Ecology: Coastal-sage scrub, chaparral
Elevation: generally < 600 m (< 2450 in PR, Santa Rosa Mtns).
Bioregional distribution: Inner North Coast Ranges (Mendocino Co.), interior San Francisco Bay Area, Outer South Coast Ranges, Southwestern California, sw edge Mojave Desert
Distribution outside California: n Baja California
Flowering time: Apr–Jul
Synonyms: var. catalinensis (Eastw.) Kearney; var. laxiflorus (A. Gray) Kearney; var. nesioticus (B.L. Rob.) Kearney (Santa Cruz Island bush mallow, CA); var. nuttallii (Abrams) Kearney; M. arcuatus (Greene) Greene (arcuate bush mallow); M. hallii (Eastw.) Kearney (Hall's bush mallow); M. mendocinensis (Eastw.) Kearney (Mendocino bush mallow, ); M. parishii (Eastw.) Kearney (Parish's bush mallow)
Highly variable, with many indistinct and intergrading local forms. Santa Cruz Island " var. nesioticus " is essentially indistinguishable from mainland " var. nuttallii "; n CA forms (e.g., " M. mendocinensi s") tend to have smaller flowers than those in s CA. Also intergrades with M. fremontii and M. davidsonii in n TR, with M. densiflorus in PR.