PLANTS CULTIVATED FOR THEIR STEMS OR LEAVES. 137 



and more recent Indian floras mention the plant as 

 cultivated.^ Several other indigoes are wild in India. 



This species has been found in the sands of Senegal,^ 

 but it is not mentioned in other African localities, and 

 as it is often cultivated in Senegal, it seems probable 

 that it is naturalized. The existence of a Sanskrit name 

 renders its Asiatic origin most probable. 



Silver Indigo — Indigofera argentea. 



This species is certainly wild in Abyssinia, Nubia, 

 Kordofan, and Senaar.^ It is cultivated in Egypt and 

 Arabia. Hence we might suppose that it was from this 

 species that the ancient Egyptians extracted a blue dye ; * 

 but perhaps they imported their indigo from India, for 

 its cultivation in Egypt is probably not of earlier date 

 than the Middle Ages.* 



A slightly different form, which Roxburgh gives as 

 a separate species (Indigofera ccerulea), and which 

 appears rather to be a variety, is wild in the plains of 

 the peninsula of Hindustan and of Beluchistan. 



American Indigoes. 



There are probably one or two indigoes indigenous in 

 America, but ill defined, and often intermixed in cultiva- 

 tion with the species of the old world, and naturalized 

 beyond the limits of cultivation. This interchange makes 

 the matter too uncertain for me to venture upon any 

 researches into their original habitat. Some authors 

 have thought that I. Anil, Linnseus, was one of these 

 species. Linnaeus, however, says that his plant came 

 from India (Mantissa, p. 273). The blue dye of the 

 ancient Mexicans was extracted from a plant which, 

 according to Hernandez' account,* difiers widely from the 

 indigoes. 



' Wight, lames, t, 365 ; Royle, HI. Himal., t. 195 ; Baker, in Mora 

 of Brit, ind., ii. p. 98 ; Brandis, Forest Flora, p. 136. 



' Gnillemm, Perrottet, and Richard, Florae Seneg. Tentamen, p. 178. 



* Richard, T&ntamen Fl. Abyss., i. 184 ; Oliver, Fl. of Trap. Afr., 

 ii. p. 97 ; Sohweinfurth and Ascherson, AufzaMung, p. 256. 



* Unger, Pflanzen d. Alt. ^gyptens, p. 66; Pickering, Chironol. 

 Arrang., p. 443. 



* Reynier, Ecoiwmie des Juifs, p. 439 ; des Egyptiens, p. 354. 

 ' Hernandez, Thes., p. 108. 



