156 
ANNALS OF THE 
Botanists have ever experienced the greatest difficulty in determining which 
are to be held merely as varieties, and which as abstract species, owing to the con- 
stant changes produced in the plants of this genus by means of cultivation. De- 
Candolle describes thirteen species in bis Prodromus, and mentions six others, but 
all of them he considers uncertain. Royle described eight; but according to 
Swartz, they are all referable to one original species. 
From Linnaeus and DcCaudolle, wo learn that the Gossypium Iierhaceum, or 
common herbaceous cotton plant, which is the species most generally culiivated, is 
a biennial or triennial plant, with a branching stem from two to six feet high, and 
palmate, hoary leaves, the lobes of which are somewhat lanceolate and acute, the 
flowers are pretty with yellow petals, and near the claw have a purple spot. The 
leaves of the involucel or outer calyx are serrate. The capsule opens when ripe, 
and displays a loose white tuft of long slender filaments, which surround the seeds 
and adhere firmly to the outer coating. This species is a native of Persia, and is 
the same which is grown so largely in the Southern States of America, in Sicily, and 
in Malta. There is another species of herbaceous cotton, which forms a shrub of 
from four to six feet high. 
The Gossypium arhoreum^ or tree cotton, is of a much larger growth. If left 
to luxuriate to its full height it has sometimes attained to fifteen or twenty feet 
The leaves grow upon long hairy foot-stalks, and are divided into five deep spear- 
shaped lobes. The tree cotton grows in India, Arabia, Egypt, China, the western 
coast of Africa, and in some parts of America. According to Humboldt this species 
of the cotton plant requires a mean annual temperature of 68 Fahrenheit ; but the 
shrubby kind may be cultivated with success under a mean temperature of 60 
to 64 ° . 
Another species is distinguished by the name of Gossypium religicsitm. Lin- 
naeus gives no reason for having bestowed upon it so singular a name. It is called 
in the Northern provinces of China, the "mie-wha," and is chiefly cultivated in a 
part of the Great Plain around Shanghae, where it is the staple summer crop. Nan- 
keen, called after the city of Nankin, is produced from the material furnished by 
this plant. It is also cultivated in the Mauritius. There are two varieties of this 
species; in the one, the cotton is extremely white, in the other it is of a yellowish 
brown. 
From the varieties which are familiar to the Southern States of America, an 
article for commerce is produced, that is divided into the technicalities, " short 
staple" and " long staple," which terms refer to the length of the fibres produced 
by the different plants. If ever any real difference in species existed between the 
plants producing these several staples, the speciality has been lost through constant 
assimilation. 
The " short staple," or upland cotton, also called bowed Georgia cotton^ from 
