This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Low branching sometimes thorny shrubs, mainly with 1-foliolate leaves, and showy clustered yellow flowers. Calyx 2-lipped; teeth long. Standard oval or ovate; wings oblong; keel oblong, deflexed, the claws of its petals adnate to the uncleft sheath of the monadelphous stamens; anthers alternately long and short. Ovary sessile, several-ovuled; style incurved at the apex. Pod various, flat in our species, several-seeded. Seeds not strophiolate. [Celtic, gen, a small bush.]
About 80 species, natives of Europe, northern Africa and western Asia, the following typical.
Genista tinctoria L. Sp. Pl. 710. 1753.
Branching from the base, not thorny, the sterile shoots decumbent, the flowering ones erect, stiff, 1°-2° high, branched above, slightly pubescent. Leaves 1-foliolate, sessile, lanceolate or elliptic-lanceolate, 1/2'-1 1/2' long, glabrous or with scattered hairs, acute at the apex, narrowed at the base, entire, shining; stipules none; racemes numerous, terminal, 1'-2' long, few-flowered; bracts ovate-lanceolate, acute; flowers yellow, nearly sessile, about 6" long; calyx bracteolate at the base, its 3 lower teeth narrower than the 2 upper; pod about 1' long, flat, glabrous.
On dry hills, Maine and Massachusetts to eastern New York. Naturalized from Europe. Native also of northern Asia. Summer. Known also as wood-wax. green-wood, dyer's-broom. dyer's green-weed, dyer's-whin and alleluia.