1889. J BOTANICAL GAZETTE. 75 



to them in their cultivation is to keep them free from weeds. 

 The roots, to the number of 5 to 9, are of the size of the 

 closed hand. The following analysis of the roots of the 

 Manihot Aipi is given: 



Water 70.29 per cent. 



Starch 14.40 



Sugar, salts and malic acid 1.01 u 



Fibrin and yellow coloring matter 08 " 



Crude fibre 3.16 



Ash 



10 82 



From the above it is seen that the roots of the tropical 

 plant are quite different from those produced in our own 

 •country. In regard to the distribution of the two varieties, 

 M. Sacc makes the following observation: 



" In Cuba I have seen only the poisonous variety. The same is true 

 of Brazil, where I have not seen the Manihot Aipi except in the JSwiss col- 

 ony, Porto Real. As to the product of the two varieties it is the same; 

 the stalks, which are the size of the finger, are from one to two metres in 

 height. I have not been able to analyze the leaves of this interesting veg- 

 etable, but, as they are much sought after by cattle, they are probably 

 very nutritious." 



The above quotation from M. Sacc's paper I have taken 

 from the Revue Agricole, published at Port Louis. Maurice, 

 vol. 2, no. 6, pp. 81 and 82. 



The name cassava should be applied properly only to the 

 purified starch derived from the roots of the plant. The 

 plant is known under the botanical names, Janipha Manihot, 

 Manihot utilissima, Jatropha Manihot, Manihot Aipi and Ja- 



tropha Lajfflingii ; it is also called the mandioc plant. The 

 fleshy root of this plant yields the greatest portion of the 

 daily food of the natives of tropical America, and its starch 

 is known in this country under the name of tapioca. Mani- 

 hot is a woody or shrubby plant, growing from fleshy tuber- 

 ous roots, the stems being smooth, the leaves being gener- 

 ally long-stalked. The leaves of the poisonous variety usu- 

 ally have seven branches palmately divided ; the leaves of 

 the sweet variety are usually only five-parted. In the "Treas- 

 ury of Botany," p. 718, the following remarks are made con- 

 cerning these two varieties: 



"It is quite clear that while the root of one is bitter and a virulent 

 poison, that of the other is sweet and wholesome, and is commonly eaten 

 cooked as a vegetable. Both of them, especially the bitter, are most ex- 

 tensively cultivated over the greater part of tropical America, and yield 

 an abundance of wholesome and nutritious food ; the poison of the bitter 

 heing got rid of during the process of preparation it undergo* -. The 

 poisonous expressed juice, if allowed to settle deposits a large quantity 



