in A. von Humboldt et al., Nov. Gen. Sp. 6: 40, pl ate 518. 1823.

Etymology: For Antoine Guillemin, 1796–1842, French botanist, author, and explorer
Treatment appears in FNA Volume 4. Treatment on page 437. Mentioned on page 406.

Herbs, perennial. Stems prostrate [or ascending], much-branched, indumentum of simple hairs. Leaves opposite, petiolate; blade linear to lanceolate, spatulate, or ovate, margins entire; basal leaves withering. Inflorescences axillary, sessile, few-flowered glomerules; bracts and bracteoles membranous. Flowers bisexual; tepals 5, connate proximally ± 1/2 its length, 1-veined; stamens 5; filaments connate basally into tube, tube adnate to calyx distally; anthers 2-locular; pseudostaminodes absent; ovule 1; style 1, ca. 0.2 mm; stigmas 2-lobed, capitate. Utricles broadly ovoid, membranous, indehiscent. Seeds 1, red-brown, lenticular-orbicular.


North America, Mexico, West Indies.


Species 5 (1 in the flora).

Lower Taxa