the screw-tree: A genus of the decandria order, belonging to the gynaecidia clas of plants; and in the natural method ranking under the 37th order, Columnifera. The calyx is monophyllous and oblique; there are five petals, and the nectarium consists of five petal-like leaflets; the capsules are intorted or twisted inwards.—There are four species, all natives of warm climates. They are shrubby plants, rising from five to fourteen feet in height, adorned with flowers of a yellow colour. They are propagated by seeds; but are tender, and in this country must be kept in a stove during the winter.