Greenwood (Dyers')Botanical Name: Genista tinctoria (LINN.)
Family: N.O. Leguminosae
Synonyms: Greenweed. Greenwood. Woad or Wood-waxen, formerly Wede-wixen or Woud-wix. Base-broom. Genet des Teinturiers. F„rberginster. Dyers' Broom.
Part Used: Whole plant.
Habitat: Mediterranean countries. Canary Islands. Western Asia. Britain. Established in the United States.
Description: The name of the genus is derived from the Celtic Gen (a small bush). Genista tinctoria is a small, tufted shrub, bearing short racemes of yellow flowers. The bright, luxuriant growth of the latter has led to its cultivation in greenhouses in the United States.
The bright green, smooth stems, 1 to 2 feet high, are much branched, the branches erect, rather stiff, smooth or only slightly hairy and free from spines. The leaves are spear-shaped, placed alternately on the stem, smooth, with uncut margins, 1/2 to 1 inch in length, very smoothly stalked, the margins fringed with hairs.
The shoots terminate in spikes of brightyellow, pea-like flowers, opening in July. They are 1/2 to 3/4 inch long, on foot-stalks shorter than the calyx. Like those of the Broom, they 'explode' when visited by an insect. The 'claws' of the four lower petals are straight at first, but in a high state of tension, so that the moment they are touched, they curl downwards with a sudden action and the flower bursts open. The flowers are followed by smooth pods, 1 to 1 1/4 inch long, much compressed laterally, brown when ripe, containing five to ten seeds.
A dwarf kind grows in tufts in meadows in the greater part of England and is said to enrich poor soil.
Cows will sometimes eat the plant, and it communicates an unpleasant bitterness to their milk and even to the cheese and butter made from it.
All parts of the plant, but especially the flowering tops, yield a good yellow dye, and from the earliest times have been used by dyers for producing this colour, especially for wool: combined with woad, an excellent green is yielded, the colour being fixed with alum, cream of tartar and sulphate of lime. In some parts of England, the plant used to be collected in large quantities by the poor and sold to the dyers.
Tournefort (1708) describes the process of dyeing linen, woollen, cloth or leather by the use of this plant, which he saw in the island of Samos. It is still applied to the same purpose in some of the Grecian islands. The Romans employed if for dyeing and it is described by several of their writers.
In some countries the buds are prepared and served as seasoning. As a dye the plant has largely been superseded by Reseda luteola.
The seeds have been suggested as a substitute for coffee.
In Spain and Italy strong cloths that take dyes well are woven from the fibres.
Constituents: The active principle, Scopnarine, is found as starry, yellow crystals, and is soluble in boiling water and in alcohol. From the liquid which remains another principle, Spartéine, is extracted, an organic base, liquid and volatile, with strong narcotic properties.
Medicinal Action and Uses: Diuretic, cathartic, emetic. Both flower tops and seedshave been used medicinally.
The powdered seeds operate as a mild purgative and a decoction of the plant has been used medicinally as a remedy in dropsy and is also stated to have proved effective in gout and rheumatism, being taken in wineglassful doses three or four times a day.
The ashes form an alkaline salt, which has also been used as a remedy in dropsy and other diseases.
In the fourteenth century it was used, as well as Broom, to make an ointment called Unguentum geneste, 'goud for alle could goutes,' etc. The seed was used in a plaister for broken limbs.
A decoction of the plant was regarded in the Ukraine as a remedy for hydrophobia, but its virtues in this respect do not seem to rest on very good evidence.
Dioscorides and Pliny speak of the purgative properties of the seeds and flowers, and the latter also regarded them as diuretic and good for sciatica. Cullen used a decoction of the young shoots for the same purpose. An infusion of the flowers has been found useful for albuminuria, and a combination of the tips with mustard, in dropsy. A poultice has benefited cold abscesses and scrofulous tumours. The infusion can be taken in wineglassful doses three or four times a day.
It has been stated that scoparine can replace all preparations, while one drop of spartéine dissolved in alcohol is a strong narcotic.
The flowers of G. Hispanica have been used in dropsy combined with albuminaric.
Dyers' Woad or Dyers' Weed is also the common name of Isatis tinctoria, and Reseda Luteola, or Yellow Weed or Weld, used in dyeing and painting.