849 FOREST CULTURE AND 
Summer temperature is needed for a prolific ecottot 
harvest. Inteiise heat, under which even maize will 
suffer, does not injuriously affect cotton, provided the 
atmosphere is not dry inthe extreme. The soil should 
not be wet, but.of a kind that naturally absorbs and 
retains humidity, without over-saturation. In arid 
regions it is necessary to irrigate the cotton-plant. 
Heavy rains at the ripening period are injurious, if 
not destructive to the cotton crop. Dry years produce 
the best returns, yet aqueous vapor in the air is nec- 
essary for the best yield. In colder localities the bolls 
or capsules continue to ripen after the frosts prevent 
the formation of new ones. Porous soils, resting on 
limestones and metamorphic rocks, are eminently 
adapted for cotton culture. The canebrake soil-of the 
North American cotton regions absorbs ammonia to a 
prodigious extent. 
Guadua angustifolia, Kunth. (Bambusa Guadua, 
Humboldt and Bonpland.)—New Granada, Ecuador, 
and probably others of the Central American States. 
This Bamboo attains a height of 40 feet, and might 
prove hardy in sheltered places of our lowlands. 
Guadua latifolia, Kunth. (Bambusa latifolia, Humb. 
_ and Bonpl.)—One of the tall Bamboos of Central Amer- 
ica, from whence several other lofty bamboos may be 
obtained, among them the almost climbing Chusqueas. 
This Guadua is stouter than any Indian Bamboo. In 
tropical America native bamboos are planted for 
hedges. 
Guizotia oleifera, Candolle. — India and probably 
also Abyssinia. The Ramtil oil is pressed from the 
seeds of this annual herb, which yields its crop in 
three months. The oil is much used, like Sesamum 
oil, as well for culinary as technic purposes. 
