ALLYSON, or ALLYSODES, Madwort; (from avesse, to be mad; because it was believed to have the property of curing madness): a genus of the filiculosa order, belonging to the tetradynamia class of plants.

Species. Of this genus, Linnaeus enumerates 19 species; but none of them are remarkable either for beauty, or any other property, except the halimifolium, or madwort with whole spear-shaped leaves. This spreads itself upon the ground, and never rises to any height. It produces, at the extremity of its branches, very pretty tufts of small white flowers; of which it is seldom destitute for six or seven months successively; for which reason it well deserves a place in the gardens of the curious.

Culture. Though these plants are natives of the southern parts of Europe; yet, if planted on a dry, lean, or rubbishy soil, they will endure our severest winters in the open air.—The halimifolium seldom continues above two or three years, and must therefore be often sown to preserve it; or if the seeds be suffered to fall, the plants will rise without any trouble. It may also be propagated by cuttings, which ought to be planted in April or May, and are very apt to take root, if kept shaded in the heat of the day, and gently refreshed with water.

This plant, as already observed, was thought to cure some kinds of madness; but the present practice has entirely rejected it for this or any other purpose.