Plants rhizomatous or stoloniferous. Stems decumbent or ascending to erect, glabrous proximally, stipitate-glandular distally. Leaf blades elliptic-lanceolate to oblanceolate, base acuminate, apex acuminate. Inflorescences pedunculate, branches stipitate-glandular. Pedicels present, stipitate-glandular. Flowers: hypanthium stipitate-glandular; sepals green or reddish, triangular to narrowly triangular; petals inconspicuous, white or greenish white; filaments white, yellow, or pink, glabrous; anthers yellow or pink. Seeds minutely tuberculate. x = 8 or 9. Penthorum chinense Pursh is known from European Russia and Asia.
Fls perfect; sep 5(-7); pet small or more often wanting; stamens 10; carpels 5(-7), united nearly to the middle, abruptly narrowed to the short styles, divergent at maturity, forming an angularly 5(-7)-lobed, 5(-7)-locular capsule with horn-shaped lobes, eventually opening by abscission of the lobes; each carpel with a pluriovulate ventral (marginal) placenta just above the united part of the ovary; perennial rhizomatous herbs with erect stems, alternate, serrulate lvs, and a terminal 2-4-branched cyme of secund greenish fls. Sometimes referred to the Crassulaceae. 3, e. N. Amer., e. Asia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.