Henophyton zigarrhenum (Maire) Gómez Campo

Oudneya zygarrhena Maire, H. deserti subsp.  zigarrhenum (Maire) Greuter & Burdet

Shrub or shrub promptly deciduous, hermaphrodite, erect, up to 40(60) cm in high, branching from the base. Bark white or whitish-greyish on old trunk and branches, green on young branchlets. Leaves alternate, linear, sessile, entire, often fleshy and spatulate, rapidly caducous and replaced by numerous linear foliar fascicles of 10-25 x 1.5-2 mm, axillary, of an intense green color that contrasts with the very white branches. Inflorescence in ± corymbiform racemes, sparse, with 3-25 flowers, on a 4-8 mm long peduncle. Calyx tubular with 4 sepals, 8 mm long, oblong, ± acute, first green and greenish-brown in full bloom, fused in its entirety except at the apex. Flowers with a violet to purple corolla, according to Maire when he described it, but the specimens we have seen in the field present it white. Corolla large, with 4 petals 15-16 mm long, with the half linear-oblong parts included in the calyx, and its terminal part suborbicular. Stamens 6, different, the 3 central exerted, the 3 lateral about 2 mm shorter and almost inserted. Filaments of the central stamens half-welded (in H. deserti they are free). The fruit is a linear silique (2.5-5.5 × 0.5-0.6 cm) upright, linear-oblong, with an acute apex (ending in a small obovate point); it usually contains between 3 and 12 seeds with a wide white wing.