Herbs, [annual, biennial, or] perennial. Rhizomes stout or slender. Stems erect to spreading, simple or branched, terete. Leaves connate proximally, petiolate or sessile; blade 3(-5)-veined, spatulate to elliptic or ovate, apex acute or rounded. Inflorescences terminal, dense to open, lax cymes; bracts paired, foliaceous; involucel bracteoles absent. Pedicels erect. Flowers: sepals connate proximally into tube, greenish, reddish, or purple, 7-25 mm, tube 15-25-veined, oblong-cylindric, terete, commissures between sepals absent; lobes green, reddish, or purple, 3-5-veined, triangular-attenuate, shorter than tube, margins white, scarious, apex acute or acuminate; petals 5 (doubled in some cultivars), pink to white, clawed, auricles absent, with 2 coronal scales, blade apex entire or emarginate; nectaries at filament bases; stamens 10, adnate with petals to carpophore; filaments briefly connate proximally; staminodes absent (present in some cultivars); ovary 1-locular; styles 2(-3), filiform, 12-15 mm, glabrous proximally; stigmas 2(-3), linear along adaxial surface of styles, papillate (30×). Capsules cylindric to ovoid, opening by 4(-6) ascending or recurving teeth; carpophore present. Seeds 15-75, dark brown, reniform, laterally compressed, papillose, marginal wing absent, appendage absent; embryo peripheral, curved. x = 7.
Infl ±congested or of open cymes; cal cylindric, membranous, 20-nerved; pet with distinct claw and blade, the appendages conspicuous, subulate; stamens 10; styles 2(3); capsule dehiscent by 4(-6) teeth; seeds rotund-reniform, uniformly reticulate; perennial herbs. 30, temp. Eurasia.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
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