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..
Perennial or biennial herbs, with ternately divided leaves, and small perfect cymose flowers. Calyx ebracteolate, small, 5-cleft. Petals obovate or cuneate, somewhat clawed. Stamens 5, opposite the calyx-segments; filaments short, subulate, persistent. Pistils 5-20; style filiform, basal. Seed ascending, attached near the base of the style. [Greek, a low rose.]
About 3 species, natives of North America and Asia. Type species: Chamaerhodos altŕica (L.) Bunge.
C. erecta Nuttallii T. & G. Fl. N. A. 1: 433. 1840.
C. Nuttallii Pickering; Rydb. N. Am. Fl. 22: 377. 1908.
Hirsute, glandular, leafy, erect, branched, 1° high or less. Basal leaves 2 - 4 - ternately divided into linear or oblong segments, those of the stem similar, but smaller and less divided; cymes numerous, pan-icled, the panicle-branches ascending; pedicels nearly erect, not longer than the flowers; calyx-tube 1" - 1 1/2" broad, hispid, the segments narrowly lanceolate, equalling or somewhat shorter than the white petals.
Plains and prairies, Minnesota to Saskatchewan, Alaska and Wyoming. June-Aug.