Butcher's-broom, or Knee-holly (Ruscus aculeatus), the only British monocotyledon with a woody stem. It belongs to the tribe Asparagineae of the order Liliaceae, and has a stout rhizome from which rise its much-branched, green, erect, angular stems, about as high as one's knee. Its numerous ultimate branches are cladodes (q.v.), or flattened and leaf-like, though leathery and springing from the axils of minute scale-leaves, and each ends in a spine. The flowers, which are sub-dioecious, spring from the upper surface of the cladodes, having small, greenish perianths of six leaves. The filaments of the stamens are united into a tube, and their anthers join alternately by their upper and lower ends, whilst the three-chambered ovary is enclosed in a barren staminodal tube, and forms a red berry-like fruit. This and the spinous branches give the plant some resemblance to a holly, and in some parts of the south of England, where it occurs in a wild state in woods, it is still used as a broom by butchers. Other species are R. racemosus, the Alexandrian laurel, with glossy spineless cladodes and a terminal raceme of flowers; R. androgynous, of the Canaries, with flowers on the margin of the cladode; R. Hypophyllum, with them on its under-surface; and R. Hypoglossum, with them between it and a similar flattened branchlet produced from its upper surface.