94 ACACIA SENEGAL 



during the prevalence of the dry desert winds from the north and 

 east which blow in the winter after the rainy season. M. C. 

 Martins has observed that the gum is excreted mostly at the 

 bifurcation of the branches, but that its production is especially 

 stimulated by the growth of a species of the parasitic genus 

 Loranthus, which he has described as Loranthus Senegal ensis. 

 This forms a large swollen base where it is inserted on the 

 Acacia -branch, and around this the excretion of gum is very 

 abundant. 



The following African species of Acacia also afford inferior gtfm. 

 They all differ from the above in having the flowers arranged in 

 globose capitula. 



Acacia tortilis, Hayne. Hayne, x, t. 31 ; Nees, t. 335. 



A. arabica, Willd. (A. nilotica, Desf. A. vera, Willd.}. Roxb., PI. Coro- 



mand., ii, t. 149, cop. in Hayne, x, t. 32; Nees, t. 333. Cultivated 



also in India. 



A. horrida, Willd. (A. capensis, Burch. A. Karroo, Hayne). Hayne, x,t. 33. 

 A. gummifera, Willd. Hayne, x, t. 28. 

 A. Seyal, Del. (A. Fistula, Schweinf.). Hayne, x, t. 30; Nees, t. 336; 



Schweinf ., 1. c., tt. 11-14 ; Berg & Sch., t. 6 d. 

 A. Ehrenbergiana, Hayne. Hayne, x, t. 29 ; Nees, t. S34. 

 A. stenocarpa, Hoclist. Schweinf., 1. c., tt. 17, 18. 



Lamarck, Diet., i, p. 19; Guill. & Perrottet, Fl. Seneg. Tent., i, 

 p. 245; Schweinfurth, in Linnsea, xxxv (1867), p. 374, and 

 Reliquiae Kotschyansc, p. 3 ; Oliver, Fl. Trop. Africa, ii, p. 342 ; 

 Benth., in Trans. Linn. Soc., xxx, p. 516; Fliick. & Hanb., 

 Pharmacogr., p. 206; C. Martins, in Bull. Bot. Soc. France, 

 1875, p. 20. 



Official Part and Names. ACACIJE GUMMI; a gummy exuda- 

 tion from the stems of one or more undetermined species of 

 Acacia, Linn. (B. P.). The gummy exudation from the stem of 

 Acacia vera, Willd., and other undetermined species of Acacia 

 yielding Gum Arabic (I. P.)- ACACIA; a gummy exudation from 

 Acacia vera and other species of Acacia (U. S. P.). 



Production, Collection, and Commerce. Acacia gum is not a 

 degradation-product like that of Tragacanth gum, which owes its 

 formation to the more or less complete transformation of the 



