A dwarf heath-like sub-shrub forming a woody root-stock from which arise numerous erect wiry stems 3 or 4 in. high. Leaves densely set on the shoot, in whorls of four, linear-lanceolate, about 1⁄12 in. long, prolonged at the apex into a mucronate tip, rounded at the base, covered with numerous sunken glands, margins strongly recurved. Flowers yellow, about 1⁄2 in. across, borne from May onwards in terminal clusters. Sepals oblong-lanceolate, often edged with stalked, black glands. Bot. Mag., n.s., t. 36.
Native of eastern and south-eastern Spain and of North Africa (Morocco and Tunisia); introduced by Dr Giuseppi in the 1930s from the Sierra de Cazorla, Andalucia; reintroduced in 1948 by P. H. Davis and V. H. Heywood from the Barranco de Gargantas in the same region. It is a rather variable species. The above description is of the form originally introduced, but the plants may be prostrate, and in some forms the leaves and flowers are somewhat larger, or the leaves blunter (Heywood, in Journ. R.H.S., Vol. 75 (1950), pp. 447-8). The North African plants are placed in two subspecies by Maire and Wilczek.
In the natural state this species inhabits crevices in limestone rocks and in cultivation is perhaps best suited to a dry-wall. It is allied to H. coris and H. empetrifolium, but its dense heath-like foliage distinguishes it.