350 xlvii. § mimose^ (oliver). [Acacia. 



and shining at the apex or stout terete and elongate. Leaves 2-3 in. 

 long, villose-pubescent, rachis with a concave sessile gland near the 

 base as well as between the upper or all of the pinnae ; pinnae in 6-11 

 pairs, leaflets in 10-18 pairs, linear, subacute, 2-2 J lines long. Pe- 

 duncles axillary, J— 1 in. long, involucel below the middle or near the 

 base. Flowers capitate. Petals united f-f their length, 2-3 times 

 longer than the obtusely 5-toothed pubescent. calyx. Legume straight 

 or but slightly curved, compressed, linear, broadly pointed or obtuse, 

 much narrowed at base, 4-6 in. long, scarcely J in. broad, in our 

 scarcely ripe specimens ; margins continuous or sinuous from abortion, 

 valves pubescent-tomentose obscurely longitudinally nerved. 



Lower Guinea. Huilla, Angola, Dr. Welwitsch ! 

 Apparently near A. abyssinica and A. Sieberiana. 



29. A. arabica, Willd. Sp. PL iv. 1085 ; Benth. in Land. Journ. Bot. 

 1842, 500. Tree varying much in size in different districts • extremities 

 glabrous or shortly pubescent-tomentose. Stipular spines straight or 

 nearly so, slender or rather stout below, varying from 0-2 or -3 in. 

 Pinnae usually in from 3-12 pairs, rachis glabrous or pubescent with 

 or without a sessile gland between the lowest and occasionally 1 or 2 

 of the upper pairs ; leaflets linear-oblong, obtuse, glabrous, or thinly 

 ciliolate, 2-2J lines long, in 10-30 pairs. Peduncles 2-6 from each 

 upper axil, occasionally somewhat racemose at the extremities, \— \\ 

 in. long, pubescent, bearing* the involucel not far from the middle. 

 Flowers capitate. Calyx shortly and obtusely lobulate. Petals united 

 nearly throughout, twice as long as the calyx. Legume linear, straight 

 or slightly curved, compressed, moniliform, the constrictions usually 

 deep, each article flat or convex, smooth, varying from \ to over f in. 

 in diameter, valves coriaceous, pubescent-tomentose or glabrous ; 4-6 

 in. long on a stipes of \-\ in. — A. vera, Willd. I.e. fide Benth. I.e. ; 

 A. nilotica, Del. Fl. iEgypt, 111. 31 and Voy. a Meroe, 22 (var. with 

 glabrous fruit) ; distributed by Hochstetter in Herb. Schimp. under 

 the names A. abyssinica and A. Adansonii, according to Richard, Fl. 

 Abyss, i. 237 ; Hayne, Arzneigew'dchse, ix. t. 32. 



Upper Guinea. Senegambia, Heudelot I and others. Niger, Barter I 



Nile Land. Abyssinia, Dillon! and others. Upper Nile (No. 769), Sp'eJce and 

 Grant ! Nubia, Dr. Schweinfurth! Both on the Blue and "White Nile. 



Lower Guinea. Bumbo, Angola (flower only), Dr. Welwitsch! 



Mozamb. Distr. Mouth of Zambesi and Rovuma river, Dr. Kirk! 



Extending eastward through Afghanistan into India ; occurring also at Natal (var. 

 Kraussiana, Benth.). 



On the Upper Nile this species attains a large size, the trunk measuring 8 or 10 ft. 

 in girth (S. and G.). The wood is used in boat-building, and the astringent pods are 

 largely used in tanning. Dr. Schweinfurth states that the quantity of gum afforded 

 (by A. nilotica, Del. — tbe form with glabrous fruit) is trifling, and does not become an 

 article of trade. 



30. A. Kirkii, Oliv. Very nearly allied to A. arabica, from which it 

 principally differs in the tuberculate articles of the legume. Spines 

 straight, slender. Pinnae in 6-8 pairs with a sessile gland between 



