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.

SIDALCEA

CHECKER MALLOW, CHECKERBLOOM

Annual, perennial herb, sometimes from long, creeping rhizomes
Stem generally erect or base ± decumbent
Leaves generally mostly from near stem base; lowest blades generally crenate to shallowly lobed, upper blades generally deeply lobed (generally ± compound)
Inflorescence generally spike- or panicle-like, generally more open in fruit; bracts at pedicel base 2, generally stipule-like; bractlets subtending calyx generally 0(–3)
Flower: calyx lobes = or > tube; petals purple or rose-pink to white; stamen-tube with generally 2 series of ± fused filaments near tip; stigmas linear, on inner side of style branches
Fruit: segments generally 5–10, indehiscent, generally ± beaked, walls thin
Seed 1 per fruit segment
Species in genus: ± 25 species: w North America
Etymology: (Greek: combination of 2 names for mallow)
Reference: [Hitchcock 1957 Univ Wash Publ Biol 18:1–96]
Highly variable and difficult, with many local forms; some plants will not key with certainty. Additional work warranted.

Native

S. malviflora (DC.) Benth.

CHECKER MALLOW

Perennial from generally well developed rhizomes and woody caudex
Stem 1.5–6 dm, generally hairy; hairs variable
Leaves variable, generally toothed or lobed; upper leaves generally much reduced
Inflorescence dense to open; lowest bracts often leaf-like, divided to base
Flower: calyx 5–12 mm in flower, generally slightly enlarged in fruit, generally densely stellate and bristly, bristles often on a swollen pad; petals 10–20(35) mm, bright to deep pink, generally white-veined
Fruit: segment 2.5–4 mm, generally coarsely pitted and net-veined (generally more so on sides than back)
Ecology: Common. Generally open, ± dry places in forest or scrub
Elevation: < 2300 m.
Bioregional distribution: California Floristic Province (except s High Sierra Nevada, Tehachapi Mountain Area, Sacramento Valley)
Distribution outside California: Oregon, Baja California
Highly variable intergrading complex with many local variants
Horticultural information: SUN, DRY or IRR: 4, 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24; CVS.

Native

subsp. californica (Torr. & A. Gray) C.L. Hitchc.

Plant gray, soft-hairy
Stem generally 6–8 dm, densely and ± coarsely stellate-bristly throughout; hairs ± 1 mm
Leaf: blade stellate on both surfaces (some hairs forked), lowest generally unlobed
Flower: calyx ± uniformly coarse-stellate (some hairs ± 1 mm)
Fruit: segment 3–3.5 mm, glandular-puberulent
Ecology: Coastal scrub, chaparral
Elevation: < 1000 m.
Bioregional distribution: s Outer South Coast Ranges, Western Transverse Ranges.