This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Annual or perennial diffusely branched stellate-pubescent herbs, with opposite entire or slightly undulate petioled leaves, and very small perfect 3-bracted flowers, solitary or clustered in the axils. Calyx of 5 equal pilose erect dry oblong I-nerved sepals. Stamens 5, hypogy-nous, their filaments united at the base, their anthers I-celled. Ovary subglobose; style short; stigma capitate or 2-lobed. Utricle globose, indehiscent. [Greek, branch-hair, from the stellate pubescence.]
About 4 species, natives of southwestern North America and Mexico, the following the generic type.
5: 166. 1833-37. Cladothrix lanuginosa Nutt; Moq. in DC. Prodr. 132:
Part 2, 360, as synonym. 1849.
Perennial, somewhat woody at the base, or sometimes annual, stem terete, much branched, sometimes thickened at the nodes, the branches prostrate or ascending, 4'-12' long. Leaves orbicular, broadly ovate or rhombic-ovate, obtuse or acute, usually narrowed at the base, entire, inconspicuously veined, rather firm, 2"-12" wide, the petioles shorter than or equalling the blades; flowers i" broad or less, mostly clustered in the axils of small upper leaves toward the ends of the branches.
In dry soil, South Dakota to Kansas, Texas, Colorado, Arizona and Mexico. June-Sept.