(From ladon, Arabic,) labdanum, cistus, cistus ladanifera, ledon Cretense. The true ladaniferous shrub. Cistus ladaniferus Lin. Sp. Pl. 737, or rather c. Creticus Lin. Sp. Pl 738. The gum labdanum is a resinous juice which exudes upon the leaves of the shrub, which grows plentifully in Arabia, Candia, and other parts of the Archipelago. The juice is collected during the summer with a kind of rake, which hath several leather thongs fixed to it instead of teeth, with which the leaves of the shrub are lightly brushed: the juice adhering to the thongs is separated with knives, and formed into regular masses for exportation. The plant grows on the sea shore; and much sand is consequently mixed with the gum.

The best sort is in dark coloured black masses, of the consistence of a plaster, which grows still softer when handled: the other is in long rolls curled up, harder than the former, but of a paler colour.

In general, this gum agrees in virtues with the balsam of* Peru; but is rarely used except in external applications. It hath an agreeable smell, and a light, pungent, bitterish taste. Rectified spirit of wine dissolves nearly the whole of the pure gum; and water takes up much of its smell and taste. By distillation with water an essential oil arises, leaving behind it a brittle resin.

Heat quickly destroys the specific flavour of this gum, which was formerly given as a pectoral and astringent in catarrhal affections and dysenteries; but is now confined to external use in the form of a plaster (see Emplastrum stomachicum), or in fumigation. See Lewis's Materia Medica; Neumann's Chemistry.