20 



ARRANGEMENT OF PARTS IN THE COTTON PLANT. 



ARRANGEMENT OF THE PETALS. 



The five petals of the cotton flower stand in alternation with the 

 five lobes of the calyx and are inserted on the base of the staminal 

 column, one petal at the base of each of the five lobes or ridges of the 

 column. Abnormal flowers sometimes occur ^\nth six or more petals 

 or with small petal-like organs on the base of the staminal column, 

 above the large petals — another indication of the relation of the petals 

 to the staminal column. 



The arrangement of the five petals of the cotton flower in the bud 



may be described as convolute; that 

 is, each petal overlaps the next. 

 Sometimes the petals overlaji to the 

 right, sometimes to the left. If the 

 intemode that bears the flower twists 

 to the right, the petals of the flower 

 overlap to the left, and ^dce versa. 



Looldng into the flower, it appears 

 that the petals and the stamens t\nst 

 in the same direction. The direction 

 of the twisting of the petals is re- 

 versed in each succeeding flower, as 

 is the case with the internode of the 

 fruiting branch which bears the flower. 

 Finally, the petals twist in the same 

 direction as the teeth of the bracts 

 and stamens of the same flower. 

 (Fig. 8.) 



ARRANGEMENT OF THE STAMENS. 



Fig. 7.-Calyxes of Cochin China Upland The COttOU floWCr haS a large clustcr 



cotton, showing intracalicary organs alter- . . ,, 



nate with calyx lobes. (Slightly en- ot stamens, ottcn Es many as 90, ail 

 •*'"s®^> inserted on a tubular sheath of tissue 



known as the staminal column. This surrounds and covers the pistil, 

 allowing only the stigmas and part of the style to project l^eyond the 

 cluster of stamens. If the style is long, as in the Egyptian cotton, 

 the stigma may be carried well above the stamens, so that insects 

 may be required for fertilization. In the Upland cottons the style 

 is generally shorter and the stigmas may remain buried among the 

 stamens, insuring self-fertilization. 



Though the stamens may at first appear to have no regularity of 

 arrangement, it is usually possible to see that they spring from five 

 vertical ridges of the staminal column, often ending in as many teeth 



222 



