Sub-shrub of the Thymelaeaceae family, endemic to the Pyrenees and the limestone massifs of northeastern Spain. It grows in rock crevices, limestone cliffs, and consolidated scree exposed to the sun, between approximately 1,000 and 2,500 meters.
It forms small, creeping, and very dense bushes, 5 to 15 cm in height, with woody, branched stems spreading over the rock. The leaves are tiny, overlapping, and arranged in tight rows along the branches, giving them an almost scaly appearance, reminiscent of certain heathers or dwarf junipers. Their color is a dark green, slightly grayish.
The species is dioecious, as its name indicates, with male and female flowers borne on separate plants. The flowers are very small, yellow, sessile, nestled in the leaf axils along the branches, with no apparent petals, the colorful effect being produced by the petaloid sepals.
In its natural habitat, its flowering extends from May to July depending on the altitude.
In cultivation, this species is among the most demanding of Pyrenean plants. It requires full sun, a very well-drained limestone substrate, and poorly tolerates stagnant winter moisture. Propagation by semi-hardwood cuttings remains uncertain, and sowing requires the presence of both sexes to obtain fertile seeds.