Family: Asteraceae

Habit: Herbs, vines, rarely epiphytes, shrubs, or trees to 30 m, sometimes aromatic or with strong odor.

Branch: Stems often hollow with a spongy pith. Leaves simple, alternate, opposite, or verticillate, rarely compound, the margins entire to lobed or dissected.

Inflorescence: Inflorescence a capitulum or head, solitary to cymose, corymbiform, paniculate, or racemose, sessile or pedunculate; the capitula of sessile, tiny flowers on a common receptacle, the flowers and subtending receptacle surrounded by a cylindrical to globose involucre of bracts or phyllaries; the phyllaries few to many, lanceolate to ovate, usually green.

Flowers: Flowers one to many per capitula, typically in the form of ray and disk florets; ray florets zygomorphic, the corolla fused in a tube below, terminating in one blade-like ligule with up to five lobes at the apex, sometimes bilabiate, often sterile; disk florets actinomorphic, fused into a tube below, terminating in five crown-like lobes at the apex; stamens five, the anthers fused into a tube around style and stigma at apex of corolla; the ovary inferior, the carpels 2, locule 1, the style often elongate, the stigma bifid or two-lobed.

Fruit: Fruit an achene, round to compressed, obconical to cylindrical; the calyx often persistent at apex in the form of scales, bristles, or hairs that help in dispersal by wind, water, or being carried by animals.

Seeds: Seeds one per fruit.

Notes: One of the largest and most variable families of flowering plants. Divided into 13 tribes, some with latex, others with spines.