A prostrate, dwarf, scarcely woody shrub only a few inches high, its young shoots very crooked, zigzagged, winged (like G. sagittalis on a small scale), the wings silky-haired beneath. Leaves few and 1⁄4 in. or less long, appressed- silky beneath, ovate, oval. Flowers bright yellow, borne at and near the end of the shoots in June in axillary and terminal clusters of three or more, but often singly or in pairs; calyx silky. Pods 1⁄2 to 3⁄4 in. long, 3⁄16 in. wide, appressed-silky, abruptly pointed, carrying three to six seeds.
A rare native of the mountains of southern France, said to be confined to the E. Pyrenees and Drôme and found mostly in rocky calcareous sites where it flowers from June to August. A very distinct and interesting as well as pretty dwarf plant for the rock garden or alpine house. The flowers individually are amongst the largest in the genus. It was excellently grown by the late Fred Stoker in Essex. A photograph of it (fig. 29) accompanies the article by him on dwarf brooms in Journ. R.H.S., Vol. 67 (1942), pp. 76-80.
G. delphinensis is closely allied to G. sagittalis, of which it was made a subspecies by Fournier in Quatre Flores de France (under Genistella).