Petasites

Perennial dioecious or gynodioecious herbs; rootstock thick. Leaves mostly basal, long-petiolate, simple, suborbicular to palmately lobed, base cordate, developing after inflorescences. Capitula few-many, radiate or discoid, in terminal corymbose panicles or racemes; involucral bracts 1- or 2-seriate, free, c. equal, herbaceous with scarious margins; bracteoles present below capitula; receptacle flat, naked. Male or bisexual capitula with numerous male tubular central florets, with or without 1–5(–10) marginal sterile ligulate or female tubular florets; female capitula with numerous tubular or ligulate female florets, usually also with a few sterile tubular central florets. Florets yellow, white, greenish, pink or purple; anthers tailed, with a triangular apical appendage; style papillose, with short obtuse branches. Cypselas obloid, glabrous; pappus of many fine simple bristles in female florets, few in males.