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a genus of annual herbs of the family Compositae. The leaves are twice or thrice pinnatisect and loosely hairy. The flower heads are solitary. The ray-florets are pistillate, and the disk-florets are yellow and bisexual. There are approximately 15 species (according to other data, 25), distributed mainly in the Mediterranean region. The USSR has two species: A. ciliatus, which has yellow ray-florets and grows in the Caucasus along the edges of mountain forests, and pellitory-of-Spain (A. officinarum), which has white ray-florets with reddish undersides. The roots contain the toxic alkaloid pelletorine, which when chewed causes profuse salivation.