FROM THE RED SEA TO THE NILE 



245 



progress across Africa by an examination of the immediate shore 

 of the narrow" sea separating Arabia from the Sudan; and this was 

 done by a five-mile tramp over saline flats and back on the lower 

 parts of the gravelly slopes. As might be expected, this brought 

 us into contact with a number of halophytes or salt plants, such as 

 Zygophyllum simplex, Suaeda vermiculata, two sedges, a half-dozen 

 grasses, a Cuscuta, a Convolvulus, a Solanum, an Acacia, and a num- 

 ber of small herbaceous and shrubby species of the "winter 



Fig. 1. Halophytic vegetation on shore of the Red Sea, near Port Sudan. 



annual" and "winter perennial" type: those which were not 

 halophytic or xerophytic being of the habit which brings them 

 from seedUng to flower in exceeding brief time (see Fig. 1). 



Here too, were great clumps of the succulent Coralluma (Fig. 2), 

 a member of the milk-weed family, of which various species were en- 

 countered extending to the summits of the mountains to the west- 

 ward and not hitherto included in the flora of Egypt except in a 

 single species which extends westward through the Mediterranean 



