A genus of perennial (or, rarely, annual) herbs or low shrubs, often aromatic, with leaves that are alternate, and much divided pinnately into narrow segments. The flower heads are tiny, usually numerous, often woolly, and gathered into racemes or panicles. The receptacle is flat and naked, and all the florets are tubular and surrounded by overlapping, scarious-edged bracts. There is no pappus. The genus includes mugworts and wormwoods. Wormwood (A. absinthium) is used for flavouring beers and other drinks; A. tridentata is sagebrush of the south-western USA. There are about 300 species, occurring mostly in dry grasslands of the northern temperate semi-arid and Arctic zones.
Subjects: Plant Sciences and Forestry.