GROUNDSEL (Ger. Kreuzkraut; Fr. seneçon), Senecio vulgaris, an annual, glabrous, or more or less woolly plant of the natural order Compositae, having a branched succulent stem 6 to 15 in. in height, pinnatifid irregularly and coarsely-toothed leaves, and small cylindrical heads of yellow tubular florets enveloped in an involucre of numerous narrow bracts; the ribbed fruit bears a soft, feathery, hoary tuft of hairs (pappus). 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 Jacobaea, ragwort, is a showy plant with heads of bright yellow flowers, common in pastures and by roadsides. The genus Senecio is a very large one, widely distributed in temperate and cold climates. The British species are all herbs, but the genus also includes shrubs and even arborescent forms, which are characteristic features of the vegetation of the higher levels on the mountains of tropical Africa. Many species of the genus are handsome florists’ plants. The groundsel tree, Baccharis halimifolia, a native of the North American sea-coast from Massachusetts southward, is a Composite shrub, attaining 6 to 12 ft. 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.
The Old English word, represented by “groundsel,” appears in two forms, grundeswylige and gundæswelgiæ; of the first form the accepted derivation is from grund, ground, and swelgau, to swallow; a weed of such rapid growth would not inaptly be styled a “ground-swallower.” If the form without the r be genuine, the word might mean “pus-absorber” (O.E. gund, filth, matter), with reference to its use in poultices for abscesses and the like.