Sp. Pl. 2: 673. 1753.
Gen. Pl. ed. 5. 304. 1754.
Subshrubs [herbs, shrubs], prostrate to erect, taprooted. Stems unarmed, hairy, hairs stellate and/or simple, sometimes also glandular. Leaves petiolate; stipules deciduous, narrowly triangular or linear-triangular; blade: margins dentate, serrate, or crenate. Inflorescences axillary, cincinni in double or compound dichasial clusters, glomerulate, or paniculiform, 5–40-flowered; epicalyx absent; bracts 4, unilateral subtending floral pair, unequal or subequal. Flowers sweet-smelling, sessile or subsessile, homostylous [mostly distylous]; sepals connate 1/2–2/3 length, nectary present; petals late-deciduous, pale-yellow, bright-yellow, or yellow-orange, usually darker in corolla throat, spatulate, clawed [rarely not clawed], lamina obovate, oblong, oblanceolate, or obtriangular; androgynophore absent or present, to 0.7 mm; stamens connate most of length [connate basally to entirely]; anthers 2-thecate, oblong or ovate; staminodes 0; ovary 1-locular, obovoid or obconic, stipitate or not; ovules 2 per locule; styles included, cylindric; stigmas 10–40-branched, apex slightly exserted above stamen apices and corolla. Fruits capsules, 1-locular, obconic, obovoid, or oblique, apically hairy, dehiscence partially or completely loculicidal. Seeds 1 (or 2) per locule, brown or black, slightly laterally compressed, obovoid, obconic, or oblique, smooth or minutely granulate; endosperm present; cotyledons oblate [widely elliptic to elliptic, circular]. x = 5, 6, 7, 10, 13.
sw, se United States, Mexico, West Indies, Bermuda, Central America, South America, Asia, Africa, Atlantic Islands, Indian Ocean Islands, Pacific Islands, Australia, tropical and subtropical areas
Species ca. 60 (3 in the flora).
Waltheria albicans Turczaninow and W. rotundifolia Schrank are found in Mexico, and apparent hybrids of them with W. indica in the broad sense occur in the United States.
|1||Capsules: endocarp corneous, to 1.3 mm from apex; bracts unequal, major bract elliptic, oblong, ovate, or obovate, minor bracts lanceolate; major bract apex obtuse or rounded and (2–)3-cuspidate or 3-dentate distally.||Waltheria detonsa|
|1||Capsules: endocarp corneous, to 1.6+ mm from apex, (sometimes thin at base and along valve margins); bracts subequal, elliptic, lanceolate, or linear, apex acute, entire distally||> 2|
|2||Calyx tube 1.7–2.5 mm; stem nodes knobby, joints extended 0.8–1 mm; leaf surface glabrate, puberulent, drying brownish olive, dark brown, bronze, or coppery; anthers ovate dehisced; styles densely white-sericeous; capsules with dense white puberulent line at apical valve margin.||Waltheria bahamensis|
|2||Calyx tube 2.5–2.9 mm; stem nodes even or extended to 0.5 mm; leaf surface tomentose or pubescent, drying olive; anthers oblong dehisced; styles hirsutulous distal to base; capsules without white puberulent line at apical valve margin.||Waltheria indica|