Purple checkerbloom Purple checkerbloom

Plants purple tinted, 0.2–0.6 m, with thick, rather woody taproot, roots often ± fleshy, with compact, rhizomelike stem bases. Stems decumbent or prostrate to ascending, base often rooting, glabrous or short stellate-hairy or sparsely bristly. Leaves mostly cauline; stipules purplish, oblong to ovate-lanceolate or ovate, 3–8 × 1–2.5 mm; proximalmost petiole 5–8(–15) cm, 3–4 times as long as blade, reduced distally to 1/2 times as long as blade, distalmost leaves subsessile; cauline blades 1.5–3(–4) cm wide, proximalmost reniform, unlobed, 1–2(–2.5) cm wide, subcordate to cuneate-based distally, margins usually coarsely crenate, surfaces sparsely short-hirsute to subglabrate, distal usually unlobed, rarely very shallowly 7–9-lobed. Inflorescences open, branched or not, calyces not overlapping except sometimes in bud, not congested in fruit, usually 2–10-flowered, 7–15 cm, elongated in age, 2–5 flowers usually open at same time, proximal flowers in axils of reduced leaves; bracts lanceolate to ovate, usually 2-fid or deeply 2-lobed, distal usually 2-fid, proximal separated to base and often with leaf remnant between, 3–4 mm, usually equaling to much shorter than pedicels, much shorter than calyx. Pedicels sometimes recurved, (2–)3–10(–30) mm. Flowers: calyx purplish, 7–11 mm, sparsely stellate-puberulent with some coarser bristles; petals bright pinkish rose, pale-veined, pistillate 8–11 mm, bisexual 11–19(–25) mm; staminal column 4–5 mm; anthers white; stigmas 6–8. Schizocarps 4–5 mm diam.; mericarps 6–8, 3–3.5 mm, sparsely glandular-puberulent on top and back, prominently reticulate-veined-pitted, mucro 0.5 mm. Seeds 1.5–2 mm. 2n = 20.

Flowering (Mar–)Apr–May(–Jul). Open coastal forests, coastal prairies, meadows; of conservation concern; 0–30 m; Calif.

Subspecies purpurea is one of the more easily recognized taxa in Sidalcea because of the purplish tint to vegetative parts, the delicate, dwarfed to prostrate habit, the limited indument, and the relatively few and small leaves and flowers. Its range is the north-central California coast in Marin, southern Mendocino, San Mateo, and northern Sonoma counties. There are some transitions to subsp. rostrata which is overall more robust and very bristly-hairy with larger, more numerous, congested flowers on shorter, thicker pedicels. Subspecies purpurea has been confused with Sidalcea hickmanii, which is more inland and has two or three involucellar bractlets attached to the base of the calyx.