Kallstroemia Scop.

Herbs, usually annual, sometimes perennial. Stems prostrate to decumbent or ascending, diffusely branched, terete, becoming ridged on drying, to 1(–1.5) m, somewhat succulent, densely hairy to glabrate. Leaves opposite, even-pinnate, one of each pair alternately smaller or sometimes abortive; stipules persistent, herbaceous, falcate, apex acuminate; petiolules very short to absent, less than 1 mm; leaflets 6–16(–20), opposite, distinct, elliptic to broadly oblong, ovate, or obovate, ± unequal in size, those on one side of rachis slightly smaller, base oblique, apex acute to obtuse, mucronate to apiculate, surfaces hairy to glabrate, terminal pair pointed forward. Pedicels emerging from axils of alternately smaller leaves, erect, usually reflexed in fruit. Flowers solitary, regular; sepals usually persistent, rarely deciduous, 5, distinct, green, equal, margins scarious, apex acute to obtuse, hairy; petals fugacious, usually marcescent, 5, convolute, spreading hemispherically, not twisted, white to bright orange, base white to bright orange or green to red, obovate, base not clawed, apex rounded to truncate, sometimes irregularly notched; nectary 5 2-lobed glands at bases of filaments opposite sepals; stamens 10, 5 opposite petals somewhat longer; filaments adnate at base to petals, filiform, subulate, or rarely basally winged, unappendaged; anthers usually ovoid to oblong [or globose], rarely linear, those opposite sepals rarely aborting; ovary sessile, 10-lobed, 10-locular, glabrous or hairy; ovules 1 per locule, sometimes 1 or more aborting; style persisting, forming beak on fruit; stigma terminal, rarely extending down distal 1/3 [almost to base] of style, 10-ridged or obscurely 10-lobed, capitate, oblong, or clavate, papillose, rarely coarsely canescent. Fruits schizocarps, ovoid [pyramidal or conic], 10-lobed, at maturity dividing septicidally and separating from persistent styliferous axis into 10, or sometimes fewer, mericarps; mericarps obliquely triangular, wedge-shaped, tuberculate, rugose, cross-ridged, or ± keeled abaxially, not spiny. Seeds 1 per mericarp, white, oblong-ovoid.