Cytisus supranubius (L. f.) O. Kuntze

A shrub 8 to 10 ft high, of broom-like habit; twigs stiff, stout, ribbed, clothed with white hairs at first, soon glabrous. Leaves of three leaflets, each 1⁄6 to 1⁄3 in. long, 1⁄12 to 1⁄8 in. wide, with a main-stalk of about the same length. Flowers fragrant, borne in May in axillary clusters on the previous season’s shoots; they are milky white with a tinge of rose, 1⁄2 in. long; standard petal roundish obovate, 1⁄2 in. long; calyx and flower-stalk hairy. Seed-pod brown, 1 to 11⁄4 in. long. Bot. Mag., t. 8509.

Native of the Canary Islands, and very abundant on the Peak of Teneriffe. It has been in cultivation at Kew but is too tender to withstand severe winters in the open there except on warm walls. It is, however, so beautiful and so distinct that it is much to be recommended for the milder parts of the British Isles. The numerous dark green branchlets resemble those of Spartium junceum and are much stouter than those of the common white broom – C. multiflorus. It has reached a height of 8 ft in the Glasnevin Botanic Garden, but was cut there by the winter of 1961–2. In the Edinburgh Botanic Garden it is fairly hardy in well-drained situations; one example has survived for twenty years on a dry bank.