20 SELECT PLANTS FOR INDUSTRIAL CULTURE 



smooth, with a girth sometimes of 12 feet. It is a yellow 

 flowering species. A. Bainesii (Baker & Dyer) is almost as 

 gigantic as the foregoing. Both doubtless yield medical gum- 

 resin like many others. A. Barberae, which is closely related 

 to A. Zeyheri, attains in Caffraria a height of 40 feet, with a 

 stem 16 feet in circumference at 3 feet from the ground. 



Aloe ferox, Miller. 



South Africa. This species yields the best Cape Aloe, as 

 observed by Dr. 'Pappe. The simply inspissated juice of the 

 leaves of the various species of this genus constitutes the Aloe 

 drug. It is best obtained by using neither heat nor pressure 

 for extracting the sap. By re-dissolving the aqueous part in 

 cold water, and reducing the liquid through boiling to dryness 

 the extract of aloes is prepared. All species are highly valu- 

 able, and can be used, irrespective of their medicinal import- 

 ance, to beautify any rocky or otherwise arid spot. 



Aloe linguiformis, Miller. 



South Africa. According to Thunberg, from this species the 

 purest gum-resin is obtained. 



Aloe plicatilis, Miller. 



South Africa. The drug of this species acts milder than that 

 of A. ferox. 



Aloe purpurascens, Haworth. 



South Africa. Another of the plants which furnish the 

 Cape aloe of commerce. The South African Aloe arborescens 

 (Miller) and A. Commelyni (Willdenow) are also drawn into 

 use for aloe, according to Baillon, Saunders, and Hanbury. 



Aloe socotrina, Lamarck, (d. vera, Linne.) 



Hills of the Island of Socotra. Extending as a native plant 

 along the Red Sea and the shores of India. Also cultivated 

 in Barbadoes and elsewhere, thus yielding the Socotrin aloe 

 and Moka aloe. 



Aloe spicata, Thunberg. 



South Africa. This also provides Cape aloe. It is an exceed- 

 ingly handsome plant. 



Aloe vulgaris, Lamarck. 



The Yellow-flowered Aloe. Countries around the Mediter- 

 ranean Sea, also Canary Islands, on the sandy or rocky sea- 



