The Probert Encyclopaedia of Nature

COMPOSITAE

Compositae is the largest known family of plants containing over 23,000 species of herbs or shrubs found all over the world. The flowers (generally called florets) are numerous (with few exceptions) and sessile, forming a close head on the dilated top of the receptacle, and surrounded by an involucre of whorled bracts. The flowers are monopetalous, and the order is divided into three natural groups from the form of the corolla: (1) Tubuliflorae, in which it is tubular, with five, rarely four, teeth; (2) Labiatiflorae, in which it is divided into two lips; and (3) Liguliflorae, in which it is slit or ligulate. The stamens are inserted on the corolla, and their anthers are united into a tube (syngenesious). The style is two-cleft at the apex. The fruit is dry and seed-like. The head of numerous florets was called by the older botanists a compound flower, hence the name. Many are common weeds, like the daisy, dandelion, thistle, etc; many are cultivated in gardens, such as the asters, marigold, etc; others have some economic or medicinal value, as chicory, artichoke, chamomile, lettuce, wormwood, arnica, etc.
Research Compositae