321 
Manihot utilissima, PoM. 
The Bitter Cassaya 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 starchj 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“ P. 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 lbs. 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 ps 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, B. 
The true Arrow-root plant. W est India. The plant is intro- 
duced intothis list notwithout hesitation, as itseems to require 
a warmer clime than ours to attain perfection. It furnishes 
most of the genuine West Indian Arrowroot, although other 
