are a very large family of more than 15,000 species; annual, biennial,
perennial herbs or sometimes shrubs. Leaves are alternate, opposite (or both on
same plant) or whorled; simple or compound. Flowers are in heads. If both ray
and disc flowers, then ray flowers are sterile or pistilate; If ray flowers only,
then flowers are perfect; If disc flowers only, then flowers are perfect; Heads
commonly surrounded by one or more series of involucral bracts; epigynous; gamopetalous;
regular or irregular; generally 5 merous; calyx interpreted to be of pappus made
up of hairs, scales, or none; petals 5, fused ; Stamens 5, usually fused by anther
sacs, epipetalous; ovary inferior, of two carpels, one locule, one seed; one style,
two stigmas with or without an appendage; individual flowers may or may not be
subtended by a bract; fruit an achene.
by Dr. Karl E. Holte, ©2001.