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. diploscypha (Torr. & A. Gray) Benth.

Annual
Stem 4–6 dm, minutely stellate and sharply bristly to tip
Leaf: stipule divided into linear segments; lobes of upper leaves generally 3-toothed or -lobed, bristly
Inflorescence: crowded clusters; bracts 8–12 mm, lobes 2–4, linear
Flower: calyx 8–12 mm, lobes lanceolate, bristly; petals 20–35 mm, minutely fringed, dark pink, center sometimes darker; outer filament series fused in sets of 5–10
Fruit: segment ± 2.5 mm, glabrous, back net-veined
Ecology: Grassland, open woodland, valleys
Elevation: < 800 m.
Bioregional distribution: Outer North Coast Ranges, Cascade Range Foothills, n&c Sierra Nevada Foothills, Sacramento Valley, Central Coast, San Francisco Bay Area
Horticultural information: SUN: 5, 6, 7, 8, 9, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24.