ACAENA (from akaina, a thorn; in allusion to the slender spines on the calyx or fruit). ORD. Rosaceae. A genus of dwarf sub-shrubby plants. Flowers capitate, or interruptedly spicate, uninteresting; petals absent. Leaves alternate, impari-pinnate. Excepting for rockwork, or as edgings to flower beds, they are not of much value; their habit is, however, very compact and neat. They require similar treatment to other hardy herbaceous plants, in ordinary soil. Increased by cuttings, creeping rootlets, divisions, and by seeds. ACAENA microphylla (small-leaved).* fl. green, small, in close heads, furnished with showy, long crimson spines. Summer. l. small, pinnate. h. 1in. to 2in. New Zealand. A neat evergreen with a compact and cushion-like growth; it is a very effective subject for the rock garden, and grows freely in most situations. The crimson globular heads of spine-formed calyces form a conspicuous and ornamental feature of the plant. SYN. ACAENA Novae Zealandiae. ACAENA millefolia (myriad-leaved).* fl. inconspicuous. A very distinct species with finely-cut pale green leaves. The fruiting spikes of this are not collected in globular heads, as in the others, and their presence detract from its value as an ornamental plant. Otherwise, it is very graceful. ACAENA myriophylla (many-leaved).* fl. green, small, in rounded spikes. June. l. pinnate; leaflets deeply cut. h. 6in. to 1ft. Chili, 1828 Small, fern-like. ACAENA Novae Zealandiae (New Zealand). A synonym of ACAENA microphylla. ACAENA ovalifolia (oval-leaved). fl. green. Summer. h. 9in. Chilli, 1868. Good for rock gardens. ACAENA pulchella (pretty).* fl. inconspicuous. A pretty bronzy-leaved species, admirably suited for rockwork crevices, where space is no object. It grows very rapidly, and forms handsome tufts.