Malvastrum hispidum (Pursh) Hochr.

Herbs, annual, (0.05–)0.1–0.5(–0.8) m, bushy-branched. Stems erect, sparsely or moderately hairy, hairs appressed, 4(–6)-rayed, normally bilateral and swollen-based. Leaves: stipules persistent, linear, 3–5 × 0.3 mm, apex acuminate; petiole 5–10 mm; blade lanceolate to linear-lanceolate, unlobed, 2.5–3.5 × 0.5–1 cm, not much reduced distally, at least 3 times longer than wide, 3–4 times longer than petiole, base rounded to cuneate, margins sparsely serrate-dentate, apex acute, surfaces stellate-hairy, hairs scattered, appressed, (2–)4–6(–8)-rayed, reduced to simple hairs at margins. Inflorescences axillary solitary flowers in distal 1/2 of plant; floral bracts absent. Pedicels 2–4(–10) mm, to 5–8(–17) mm in fruit; involucellar bractlets free from or basally adnate to calyx for 0.5–1 mm, narrowly lanceolate to linear, subfalcate, 3–7 × 0.3–0.6 mm, 1/2 times length of calyx lobes, apex acuminate. Flowers: calyx connate 2/5–1/2 its length, broadly campanulate, distinctly plicate-angular due to prolonged reniform-auriculate lobe bases, 5–7 mm, accrescent to 8–10 mm, somewhat inflated in fruit, surface hairy, hairs both 4–6-rayed, stellate and simple to 2-rayed marginal; corolla wide-spreading, yellow to pale yellow-orange, 5 mm diam., petals asymmetrically obovate, shallowly lobed, 3–4.5 × 2–3.5 mm, subequal to or exceeding calyx by 0.5–1 mm; staminal column 1–1.6 mm, glabrous; style 5-or 6-branched. Schizocarps 6–8 mm diam.; mericarps readily shed from calyx, 5 or 6, 2.6–3.5 × 2.6–3.5 × 1.5 mm, dehiscent, separating into 2 valves, short-notched, mucro absent, hairy, hairs both minute, simple and longer erect, simple, to 1 mm on proximal-apical surface, sides rounded, smooth and unribbed. Seeds 2–2.5 mm. 2n = 36.