73 



Manihot utilissima, Pohl. 



The Bitter Cassava or Tapioca-plant. Tropical South 

 America. Closely allied to the former, producing varieties 

 with roots of poisonous acridity, and with tubers perfectly 

 harmless. The tubers attain a length of 3 feet ; they can 

 be converted into bread or cakes, the volatile poison of 

 the milky sap being destroyed through pressing of the 

 grated root in first instance, and the remaining acridity is ex- 

 pelled by the heating process. The starch, heated in a moist 

 state, furnishes the Tapioca. Manihot is abundantly culti- 

 vated at Caracas, where the singularly uniform temperature 

 throughout the year is only 60 to 70 F. It is a very 

 exhausting crop, and stands thus in need of rich soil and 

 manuring. The propagation is effected by cuttings from 

 the ligneous part of the stem. The soil, destined for Cassava, 

 must not be wet. In warm countries the tubers are avail- 

 able in about 8 months, though they still continue to grow 

 afterwards. The growth of the plant upwards is checked 

 by breaking off the buds. The Bitter Cassava is the more 

 productive of the two. The yellowish tubers attain some- 

 times a weight of 30 Ibs. They do not become soft by boil- 

 ing like Aipi. 



Maoutia Puya, Weddell. 



India, on mountains up to 4000 feet. It is taller than 

 Boehmeria nivea, and furnishes a similar fibre. This shrub 

 belongs to a tribe of the nettle order, not possessing 

 burning acridity. None of the true nettles, such as the 

 Girardinias, nor allied stinging plants have been recom- 

 mended in this index, although from some an exquisite 

 fibre L is derived, as the writer wishes to guard against the 

 introduction of any burning species, which possibly might 

 disseminate itself in a mischievous manner in our ranges, 

 and then probably could not again be suppressed. 



Maranta arundinacea, L. 



The true Arrow-root plant. West India. The plant is intro- 

 duced into this list not without hesitation, as it seems to require 

 a warmer clime than ours to attain perfection. It furnishes 

 most of the genuine West Indian Arrowroot, although other 



