Amer. Naturalist 17: 875. 1883.
Herbs, annual, rarely perennial, (0.2–)0.3–0.5(–0.9) m, not glaucous, with taproot or rhizomelike stolons to 35 blade; basal blades usually orbiculate, unlobed or slightly palmately lobed, 1–2(–10) × 2–5(–10) cm, wider than long, margins crenate, shiny; cauline blades rounded, deeply 5–9(–11)-lobed, 1–2 × 2–4 cm, lobes linear-elliptic to oblanceolate-obtuse, margins entire, ciliate, surfaces slightly hirsute. Inflorescences erect, spicate, dense, calyces sometimes overlapping, unbranched or branched, distal stem sometimes leafless, many-flowered, not 1-sided, 2–10 cm, elongating at maturity; bracts green or purplish, ovate to wide-elliptic, usually 2-fid, sometimes undivided, 2–6(–12) × 2–5 mm. Pedicels (2–)4–5 mm; involucellar bractlets absent. Flowers bisexual or infrequently unisexual and pistillate, plants gynodioecious; calyx often purple tinted or scarious, 4–12 mm, silky strigose-bristly at base and on veins, stellate-puberulent; petals usually pale purple or pink, rarely white, base pale or white, (9–)10–25 mm, pistillate shortest; stamens: outer filaments connate to apex, tube funnel-like, with continuous rim to which unstalked anthers attach; staminal column 4–9 mm, hairy in proximal 1/2; anthers white to pale purple; stigmas 5–9. Schizocarps 5–9 mm diam.; mericarps 5–9, often purple tinted, 2.5–4.5 mm, glabrous, not especially roughened, sides reticulate-veined, back deeply longitudinally grooved, mucro often appressed, 0.5 mm. Seeds 2–3.5 mm.
Sidalcea calycosa is variable and found locally in marshes and vernal pools in northern California. The annual, short-taprooted, subsp. calycosa varies in height and branching and is consistent in other vegetative and reproductive features. The perennial subsp. rhizomata has elongated, amphibious stolons somewhat like those of the fern Marsilea and is found in marshes near the coast. It and subsp. calycosa have the same fragile nature and similar morphology, and their distinctive fruits are essentially indistinguishable, having the only multifurrowed or striate surfaces in Sidalcea. Because S. calycosa is not at all fibrous and tough like the other perennials, it is keyed with the annuals.
Subspecies 2 (2 in the flora).
|1||Plants annual, with taproot, stem base rarely decumbent, rooting; bracts 2–6 mm, not obscuring calyx, glabrous or ciliate; calyces 4–7 mm; petals (9–)10–25 mm; relatively widespread in n, c California.||Sidalcea calycosa subsp. calycosa|
|1||Plants perennial, with rhizomelike stolons rooting at nodes; bracts 8–12 mm, mostly obscuring calyx, silky-hairy; calyces 6–12 mm; petals 20–25 mm; restricted to n, c coastal California.||Sidalcea calycosa subsp. rhizomata|