SOLANACE^ 



599 



cence. That the tobacco plant is, in all probability, natu- 

 rally close-fertilized, is borne out by the fact that self-fertili- 

 zation (inbreeding) under control has not resulted in a loss 

 of vigor. 



Fig. 244. — Tobacco (Nicotiana tabacum). A, flower; B, pistil; C, corolla 

 cut open and spread out flat; D, cross-section of young fruit; E, lengthwise 

 section of young fruit. (After Strasburger.) 



Fruit. — The fruit (Fig. 244) is a two- to four-valved cap- 

 sule, bearing numerous small seeds. A single plant may 

 produce as many as a million seeds. 



Geographical. — This species is indigenous to tropical South America. Its 

 varieties are now in cultivation throughout subtropical and even temperate 

 climates. It occasionally escapes from cultivatioQ and runs wild. It is 

 grown commercially only in the humid sections of this country. 



