Convolvulus hystrix subsp. hystrix

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

104a. Convolvulus hystrix subsp. hystrix Figure 13, t. 26-34

Convolvulus spinosus Forssk., Fl. Aegypt.-Arab. cvi. 1775, nom. illeg., non Convolvulus spinosus Burm.f. (1768). ( Forsskål 1775: cvi). Type. YEMEN, Bait al Faqih, Forsskål (holotype C, isotype BM000049217).

Convolvulus armatus Delile, Descr. Egypte, Hist. Nat. 189. 1813. ( Delile 1813: 189). Type. EGYPT, Red Sea, Delile s.n. (holotype MPU; isotype P!).

Convolvulus hystrix subsp. dhofaricus R.R.Mill, Edinburgh J. Bot. 70: 373. 2013. ( Mill 2013: 373). Type. OMAN, Dhofar, Miller & Nyburg 9288 (holotype E!; isotype K!).

Distinguishing features.

Plant spiny with numerous short spine-like lateral branchlets arising on the main spinescent branches.Stems and leaves pubescent to pilose. Flowers in clusters of up to 6 forming a suborbicular head; bracteoles obovate, about as broad as long, corolla 1.2-1.4 cm long. Sa’ad 1967: 75; Collenette 1999: 229 (photo); Boulos 2000: 331.

Distribution.

Red Sea coastal regions of Egypt (Boulos & Tackholm s.n. [12/3/1965]), Sinai (Danin s.n. [27/3/1971]), Sudan (Schweinfurth 2151), Eritrea (Bally 6913), Djibouti, Somalia (Gillett 4735, Collenette 38), Saudi Arabia (Kercher 44, Zohrab 5) and Yemen (Wood Y/75/2); also in the Hadramaut region of Yemen (Woodford 31, Thulin et al. 9559) and the Dhofar region of Oman (Miller & Whitcomb 2050, Miller & Nyberg 9288).

Note.

The type of subsp. dhofaricus (Miller & Nyberg 9288) is an exceptionally villous specimen but there exist many intermediate specimens with more typical Convolvulus hystrix and we do not think this taxon merits recognition. There are also plants with strikingly sericeous stems and leaves in Dhofar (Miller 6326a).