Convolvulus hystrix Vahl, Symb. Bot. 1: 16. 1790. (Vahl 1790: 16).

Wood, John R. I., Williams, Bethany R. M., Mitchell, Thomas C., Carine, Mark A., Harris, David J. & Scotland, Robert W., 2015, A foundation monograph of Convolvulus L. (Convolvulaceae), PhytoKeys 51, pp. 1-282 : 129

104. Convolvulus hystrix Vahl, Symb. Bot. 1: 16. 1790. (Vahl 1790: 16).

Type.

Based on Convolvulus spinosus Forssk., non Convolvulus spinosus Burm.f.

Description.

Subshrub, much branched with entangled spinescent branchlets to 1 (- 2) m, vegetative parts glabrous, sericeous, pubescent or densely pilose. Leaves subsessile, 4-10 (-15) × 1-3 (-5) mm, narrowly oblong, elliptic or ovate, acute, base broadly cuneate, truncate to auriculate, margin entire. Flowers 1-6 in subsessile, elliptic to suborbicular axillary clusters; peduncles absent; bracteoles 3-7 × 2-5 mm, narrowly elliptic to obovate; pedicels 0-1 mm; outer sepals 7-9 × 6-8 mm, broadly ovate or elliptic, acuminate, wider than inner ones; corolla 0.8-1.4 cm long, pale to dark violet, weakly lobed, midpetaline bands pubescent, brown; ovary glabrous; style glabrous, divided 6-7 mm above base, arms unequal c. 1-1.5 mm, stigmas short and narrowly elliptic, c. 1 mm. Capsule glabrous; seeds glabrous.

Notes.

Within Arabia and along the Red Sea this species is reasonably constant although there is variation in whether hairs are appressed or spreading and in the number of flowers in each head, but much of this variation seems random geographically. In Somalia variation is much greater and three subspecies are here recognised: