Acacia.] xlvii. § mimose^e (oliver). 339 



Involucel between the extremities of peduncle. 



Legume straight or nearly so. (Compare A. Adansonii, 

 p. 353, and A. verugera, p. 354.) 

 Legume continuous (margins parallel). 

 Pinnae 2-12 pairs. Legume 1-3 in. long. 



Leaflets 6-15-jugate, 2-3 lines long ; legume 



margin subalate, puberulous, grey 25. A. nubica. 



Leaflets 6-15-jugate, 3-4 lines long; legume 



margin not alate 26. A. robusta. 



Leaflets 14-30-jugate, 1-1^ lines long; legume 



glabrous, broad 27. A. etbaica. 



Pinnae 10-30 pairs. Legume 5-6 in. long . . . 21. A. Sieberiana. 

 Pinnae 6-11 pairs. Legume 4-6 in. long, pubescent 28. A. tristis. 

 Legume constricted between the seeds. 



Valves not tubercled 29. A. arabica. 



Valves tubercled ._ 30. A. Kirkii. 



Legume falcate, not twisted, not exceeding i in. broad. 

 Pinnae in 3-10 pairs. 



Legume broadly constricted, ^-\ in. broad . . .31.-4. Seyal. 

 Legume scarcely or not constricted, £ in. broad . 32. A. stenocarpa. 

 Pinnae in 1-2 pairs. Legume broadly constricted . 33. A. Ehrenbergiana. 

 Legume spirally twisted. 



Legume puberulous or pubescent 34. A. spirocarpa. 



Legume glabrous 35. A. tortilis. 



1. A. albida, Delile, Fl. ^gypt. 142, t. 52, 3. A large tree, much 

 divaricate!}' branched, with whitish or .pale grey bark ; extremities 

 wholly glabrous or puberulous. Stipular spines straight, spreading, 

 rather stout at base, usually not exceeding J -fin., frequently much 

 shorter or rudimentary. Leaves glabrous or puberulous ; rachis usually 

 from J— 3 in. in length with a sessile gland between each of 4—6 (2-8) 

 pairs of pinnae ; leaflets oblong, mucronulate, the midrib very oblique, 

 in 7-17 pairs, lj — 3 (4) lines long. Spikes axillary, solitary or gemi- 

 nate, with peduncle 2^-5 (7) in. long. Flowers sessile, " white," 

 glabrous (or pubescent in A. saccharata). Calyx short, cupuliform, 

 broadly toothed, glabrous or puberulous. Petals free nearly from the 

 base, 4 times longer than calyx. Legume flat, oblong, arcuate, often 

 sinuous on the outer suture, valves coriaceous, often transversely 

 nerved and reticulate or at length smooth, 2-4 or 5 in. long, -J-l (1 J) 

 in. broad, on a very short stipes. — A. saccharata, Benth. in Lond. Journ. 

 Bot. 1842, 505 ; A. gyrocarpa, Hochst. in Schimp. PL Abyss. 



Upper Guinea. Senegambia, Robert] Lelieur! A pubescent unarmed form 

 (.4. saccharata, Bth.), Heudelot ! 



Nile Land. Abyssinia, Schimper! Capt. Pollen! Nubia, Pethericlc ! and 

 others. Upper Nile, Spehe and Grant! Schweinfurth. 



Lower Guinea. Mossamedes, Dr. Welwitsch! A noble form, pubescent both ex- 

 tremities and leaves, the racemes with peduncle 6-7 in. long, and the straight or arcuate 

 flat legumes rather over 1 in. broad. 



Mozamb. Distr. Zambesi, Dr. Kirk ! 



To this species I would also refer with doubt, A. mossambicensis, Bolle in Peters' 

 Mossamb. Bot. i. 5. I do not observe any character in the published description by 

 which it differs, excepting in the absence of spines. This, however, occurs occasionally 

 in A. albida. 



