19. Sidalcea malviflora (de Candolle) A. Gray, Smithsonian Contr. Knowl. 3(5): 16. 1852. (as malvaeflora).
California checkerbloom California checkerbloom
Sida malviflora de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 1: 474. 1824 (as malvaeflora); Nuttallia malviflora (de Candolle) Fischer & Trautvetter
Herbs, perennial, colonial or not, 0.2–0.6(–1.1) m, not glaucous, with woody caudex, usually with woody taproot, without rhizomes or rhizomes not cordlike, 3–10 mm diam. Stems clustered or scattered, erect to ascending, or decumbent to suberect, sometimes rooting, unbranched or branched, solid, usually densely to sparsely hirsute, stellate-hairy, or glabrescent, hairs 1–2 mm, distal stem usually more sparsely hairy to glabrate. Leaves basal and/or cauline; stipules green or purplish, linear-lanceolate or wide-lanceolate to oblong or ovate, 3–8(–12) × 1–3.5(–5) mm, often hairy to ciliate; petioles of proximalmost leaves (5–)6–15(–30) cm, 3–9 times as long as blades, much reduced distally to 1/2–2 times as long as blade; blades: proximalmost usually orbiculate, sometimes reniform, unlobed or shallowly lobed, (1–)4–15 × (1–)4–12 cm, base cordate, margins crenate, apex rounded, surfaces hairy, hairs stiff, either or both simple and stellate or forked, lobes cuneate-obovate, margins dentate; mid stem unlobed or palmately 5–9-lobed, margins coarsely crenate-serrate, lobes toothed or lobed to dissected; distalmost smaller, sometimes subsessile. Inflorescences erect or somewhat ascending, dense, subcapitate or spicate especially when young to elongated and open, calyces overlapping or not, not long-pedunculate, usually unbranched, 2–21-flowered, usually light or bright pink to lavender or dark rose-purple, rarely white, pale-veined, 7–20(–30) mm, pistillate 7–11(–30) mm, bisexual 10–25(–30) mm; staminal column 4–8 mm, hairy; anthers white to pale pink or pale yellow; stigmas (6 or)7 or 8(or 9). Schizocarps 4–8 mm diam.; mericarps (6 or)7 or 8(or 9), 2.5–4 mm, usually minutely hirtellous, stellate-puberulent, or glandular, rarely glabrous, roughened, sides ± honeycomb-pitted and reticulate-veined, back less so, mucro 0.3–1 mm. Seeds 1.5–3 mm. 2n = 20, 40, 60.
Subspecies 7 (7 in the flora): w United States.
Sidalcea malviflora includes local variants and intermediates. It was first described as a coastal taxon; later researchers subsequently included interior populations that shared a few characteristics. Molecular study has shown that the majority of the interior plants are not very closely related to the coastal forms; the species is again considered to be primarily coastal. Two inland taxa remain, subspp. californica and dolosa.
Sidalcea malviflora can generally be distinguished by its coastal distribution, its decumbent-based stems, its relatively short pedicels, its relatively large and showy petals that usually have conspicuous whitish veins, especially when dry, and its generally prominently reticulate-pitted and usually glandular-puberulent mericarps that have a mucro. The leaves can be extremely variable, from unlobed to highly dissected; the indument tends to be harsh to the touch.