Herbs, annual or perennial with woody bases. Taproots slender to stout Stems erect or ascending, simple or branched proximally, terete or angular. Leaves connate proximally into sheath, sessile; blade 1- or 3-veined, linear to narrowly oblanceolate, apex acute. Inflorescences terminal, dense capitula or lax cymes, or flowers solitary; bracts paired, brown-scarious and often enclosing inflorescence; involucel bracteoles of 1-3 pairs [or absent], similar in size and texture. Pedicels erect. Flowers bisexual, occasionally unisexual and female; sepals connate proximally into tube, 4-15 mm; tube green or reddish and white or brown-scarious, 15-veined, cylindric, terete, commissures between sepals veinless, broad, scarious; lobes green, reddish, or brown, 3-veined, oblong, shorter than tube, margins white or brown, scarious, apex rounded; petals 5, pink or purplish to white, clawed (or not in P. saxifraga), auricles absent, coronal appendages absent, blade apex entire and obtuse to 2-fid to 1/ 16 of length; nectaries at filament bases; stamens 10; filaments distinct; staminodes absent; ovary 1-locular; styles 2, filiform, 2-9 mm, glabrous proximally; stigmas 2, linear along adaxial surface of styles, papillate (30×). Capsules 4-lobed, oblong, shorter than sepals, opening by 4 slightly recurving or straight teeth; carpophore present. Seeds 8-15, blackish brown, shield- or helmet-shaped, dorsiventrally compressed, reticulate to papillate, marginal wing absent, appendage absent; embryo central, straight. x = [13?, 14?], 15.