the Rock-rose: A genus of the monogynia order, belonging to the polyandria class of plants; and in the natural method ranking under the 26th order, Rosaceae. The corolla is pentapetalous; the calyx pentaphyllous, with two of its leaves smaller than the rest. The seeds are contained in a capsule. There are 37 species, most of them natives of the southern parts of Europe, but hardy enough to bear the open air in this country. They are beautiful evergreen shrubs, generally very branchy quite from the bottom, and forming diffused heads. They are very ornamental in gardens, not only as evergreens, making a fine variety at all seasons with their leaves of different figures, sizes, and shades of green and white, but also as first-rate flowering shrubs, being very profuse in most elegant flowers of white, purple, and yellow colours. These flowers only last for one day; but there is a continual succession of new ones for a month or six weeks on the same plant; and when there are different species, they will exhibit a constant bloom for near three months. They are propagated either by seeds or cuttings, and thrive best in a dry soil. Their proper situation in shrubbery works should be towards the front of the clumps and other compartments, in assemblage with the choicest shrubs of similar growth, disposing them so as to make a variety, and to have shelter from the other plants; but they ought by no means to be crowded. Gum labdanum is found upon a species of cistus which grows naturally in the Levant, and is therefore called Labdanum. See Labdanum.