An evergreen shrub 1 to 11⁄2 ft high, with erect branches that are downy when young. Leaves opposite, narrowly linear, 1 to 21⁄2 in. long, 1⁄20 in. wide, grooved on the upper side, rough or bristly at the edges, rather triangular in cross-section. The tiny flowers are produced from June onwards crowded in an ovoid head scarcely 1⁄2 in. long, which is borne at the end of an erect, slender, downy stalk 11⁄2 to 31⁄2 in. long. Corolla 1⁄8 in. wide, four-lobed, yellowish white, the lobes lanceolate, just standing clear of a mass of broadly ovate bracts, which are green, pointed, and have a membranous, rather transparent margin.
Native of Central and S. Europe; cultivated by Gerard at Holborn in 1596, under the name Psyllium sempervirens. It is of interest as a shrubby member of the same genus as the common lawn pests, but has no beauty. It was found by Charles Baker flowering on Foxendown, Meopham, Kent, in August 1920, and H. N. Ridley has a note on its existence there in the Journal of Botany for 1920, p. 271. It was growing on a dry bank of chalk where there is very little soil, and, as there are no houses near the spot, Ridley considered it quite unlikely that a plant of so little attraction and so very rarely cultivated as this could have gained its footing there as an escape from gardens. He is, therefore, inclined to include it in the indigenous flora of England. But C. E. Britton, at p. 294 of the same journal, suggested it had most probably been introduced with imported seeds. He had found it in 1902 on the slopes of a Kentish hill between Cobham and Luddesdown.