Missouri Botanical 

 Garden Bulletin 



Vol. IX St, Louis, Mo ., November, 1921 No. 9 



COTTON 



Although a considerable amount of cotton is grown in Mis- 

 souri, its culture is confined chiefly to the southeastern section 

 of the state which has a longer growing season than this 

 locality. The length of time required to bring a crop of cotton 

 to maturity depends upon various factors, chief among them 

 being the kind of cotton and the temperature. At least six 

 mouths is required to mature cotton in St. Louis, and the 

 plants grown in the economic garden at the Garden were 

 started indoors in order to insure their ripening before frost. 



Only the herbaceous or shrub-like forms of cotton are 

 grown in this country. In the southern states the much- 

 branched cotton plant attains a height of about four feet. 

 The flowers are yellow and as they age turn to a deep rose. 

 The boll gradually swells until it attains the size of a walnut 

 and at maturity splits, exposing the several cells which hold 

 the numerous seeds with their copious covering of fibers known 

 as lint. This lint becomes the cotton of commerce after pass- 

 ing through various stages of manufacture. 



To the naked eye a cotton fiber is round and smooth, but 

 upon examining it under a microscope it will be found to be 

 very much twisted— a characteristic which adapts it so readily 

 to spinning, no other vegetable or animal fiber possessing this 

 peculiar twist. These hairs are the result of the elongation of 

 certain epidermal cells of the seed coats. Immature cotton 

 does not have the proper number of twists and it also lacks 

 strength and is slow to take dye. Not all of the fibers are 

 of the same length, and while mature seed is clothed in many 

 long hairs a fuzz is also present. That cotton may qualify 

 for the highest market value it is essential that the floss be 

 as near one length as possible and mature uniformly. The 

 floss of mature cotton assumes certain tints depending upon 



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