Perennial of the Asteraceae family, Hieracium eriophorum is a hawkweed endemic to the southwest of France, strictly confined to the Atlantic heaths and sandy grasslands, mainly in the Landes de Gascogne massif. It colonizes the poor, acidic, and well-drained siliceous soils there, in full light, at low altitude.
It forms a dense and sprawling basal rosette, remarkably low-growing, whose height in the vegetative stage rarely exceeds a few centimeters. The foliage is the main attraction and the most immediately striking feature of this species: the leaves, oval to spatulate, dark green, are covered with an extraordinarily dense woolly tomentosity, forming a mass of silky white filaments, tangled and fluffy, which literally envelops the entire rosette. This woolly covering, reminiscent of a tuft of cotton or raw wool, is unique in the genus in Western Europe and earns the plant a special place in any collection.
The floral stems, slender and also tomentose, rise to 20–40 cm and bear bright yellow capitula characteristic of the genus, with well-developed ligules distinctly toothed at their top.
In its natural environment, its flowering extends from June to August. In cultivation, it requires a sandy, poor, acidic, and perfectly drained soil, in full sun; any stagnant moisture at the heart of the rosette is fatal to it. It is a demanding collector's plant, to be reserved for specialists of Mediterranean-Atlantic species.