This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Introduced. Perennial. Propagates by seeds and by woody, creeping rootstocks.
Time of bloom: June to July.
Seed-time: July to August.
Range: Maine to Massachusetts and eastern New York.
Habitat: Dry uplands.
Time was when the clothing of a New England household was spun, woven, and dyed at home; then the Genista was cultivated as a useful and necessary plant. Used by itself, it colored woolen cloth yellow; combined with Woad (Isatis tinctoria), a blue-dye plant of the Mustard Family, it dyed green. But, its usefulness gone, it was left uncared for and "escaped," becoming so abundant in some localities that dry upland pastures are sometimes yellow in summer with its bloom. Cattle will eat it when other forage is scarce, with the result that its bitter taste is imparted to the dairy products. (Fig. 160.)
Fig. 160. -Dyer's Greenweed (Genista tinctoria).
Stems usually not much more than a foot high, hard and woody, branching freely from the base, round, ridged, and without thorns. Leaves alternate, lance-shape to elliptic, sessile, entire, smooth and shining. Flowers in spiked racemes, each flower about a half-inch long, like a golden-yellow pea-blossom, sessile, with a small bract at its base. Pods about an inch long, smooth, and flat, each containing several seeds which are very long-lived.
Frequent and persistent cutting close to the ground, beginning at the first bloom and allowing no leaf-growth throughout the growing season. More than one season of such persistent root-starvation may be required in order to subdue the weed, but, if not permitted to refill its underground storehouses with sustenance, it must succumb.