ASTERACEAE, Aster Family

Herbs; rarely dioecious; leaves alternate, opposite, or whorled; flowers bisporangiate, monosporangiate, or neutral, epigynous, in dense heads on a common receptacle surrounded by an involucre of bracts (phyllaries); pappus in position of calyx, of hairs, bristles, awns, teeth, or scales. or cuplike, or absent; corolla tubular and usually regular, usually 5-lobed, or ligulate and zygomorpbic (tubular at base but flat and straplike above); heads discoid (of flowers with only tubular corollas); ligulate (of flowers with only ligulate corollas), or radiate (of a central disk of flowers with tubular corollas surrounded by one or more series of flowers with ligulate corollas, called ray flowers); flowers subtended by bracts (scales), receptacle then chaffy, or flowers bractless, receptacle then naked; stamens 5, inserted on the corolla, filaments separate, anthers usually united around the style or rarely separate or scarcely united; carpelsĀ 2. united; ovary 1-loculed with 1 ovule; style 1, usually 2-branched at apex; stigmas 2; fruit an achene. (Compositae. nom. altern.)

Asteraceae