(From the Hebrew word azab, a holy herb, or a herb appointed for cleansing holy places). Hyssop. Symphytum petraeum; hyssopus officinalis Lin. Sp. Pl. 796, is a low shrubby plant, with brittle branched stalks, square when young, but round when old. The leaves are oblong, narrow, and of a dark green colour; the flowers in loose spikes, of a blood colour. It is perennial, cultivated in gardens, and flowers in July and August.

The leaves have an aromatic smell, and a bitterish, warm taste. Water extracts the greater part of their virtues, but spirit more perfectly; and the extract made by evaporating the spirituous tincture scarcely loses any degree of the virtues of the plant. From about six pounds of leaves an ounce of essential oil may be obtained by distilling in water.

This plant is esteemed as an attenuant, corroborant, and expectorant; useful in humoral asthmas, coughs, and other disorders of the breast and stomach, accompanied with inflammatory symptoms. These virtues are, however, much disputed by modern writers, particularly Cullen. In these cases an infusion of the leaves may be sweetened with honey, and drunk at pleasure by those who still entertain a favourable opinion of this medicine. In a fomentation and poultice, in contusions, and for removing the blackness occasioned by the ecchymosis, hyssop has been considered an efficacious remedy. See Lewis and Cullen's Materia Medica.

Hyssopus capitata. See Serpyllum vulgare.