Encyclopædia Britannica, Ninth Edition/Groundsel
GROUNDSEL (German, Kreuzkraut; French, Seneçon), Senecio vulgaris, Linn., is an annual, glabrous or more or less woolly plant of the natural order Compositæ, series Tubulifloreæ and tribe Senecionideæ, having a branched succulent stem 6 to 15 inches in height; pinnatifid and irregularly and coarsely-toothed leaves; flowers in separate corymbs, with involucres of about 20 equal and several external and smaller bracts, and florets yellow and tubular, rarely ligulate in the marginal row; and ribbed and silky fruit. The plant is indigenous to Europe, whence it has been introduced into all temperate climates. It is a troublesome weed, flowering throughout the year, and propagating itself rapidly by means of its light feathery fruits; it has its use, however, as a food for cage-birds. Senecio sylvaticus and S. viscosus are known respectively as mountain groundsel and stinking groundsel. Many species of the genus are handsome florists' plants. The groundsel tree, Baccharis halimifolia, Linn., a native of the North American sea-coast from Massachusetts southward, is a Composite shrub, attaining 6 to 12 feet in height, and having angular branches, obovate or oblong-cuneate, somewhat scurfy leaves, and flowers larger than but similar to those of common groundsel. The long white pappus of the female plant renders it a conspicuous object in autumn. The groundsel tree has been cultivated in British gardens since 1683.
See Loudon, Arboretum, vol. ii., 1838; Syme, Sowerby's English Botany, vol. v., 3d ed., 1866.