CHAPTER XIX 

 ANGIOSPERMS 



COMPARISON OF THE DIVISIONS OF PLAXTSi 



293. The most diverse group of plants. The second class of 

 spermatophjtes, the angiosperms, is the highest group of the 

 liighest division of the plant kingdom. The number of indi- 

 viduals of this class is very great. Only one other group, the 

 fungi, compares favorably with it in number of species and 

 of mdividuals. There is a difference of opinion as to how 

 many angiosperms there are, but all agree that there are over 

 100,000, and doubtless there are many undescribed species 

 yet to be added. Xot only is the number of species and num- 

 ber of individuals verj- great, but the variation in form and 

 habit covers almost every imaginable condition. There are 

 submerged water plants, free-floating plants, plants growing 

 in water part of the time and on land part of the time. They 

 grow in some regions so dry and so exposed that it would seem 

 nothing could live ; they thrive luxuriantly in the tropics, and 

 they even live upon the ice in frigid regions. They may be epi- 

 phytic, may live as vines upon other plants, or may be para- 

 sites, saproph3'tes, and even carnivorous plants. In form the 

 angiosperms range from diminutive floating disks to gigan- 

 tic trees. In length of life they range from forms that pass 

 from adult plant to plantlet and to adult again, several times 

 each season, to individual plants which live to be several cen- 

 turies old. The class contains plants that produce our most 

 necessary foods, and others that are deadly poisons. 



1 This chapter completes the study of the great groups (Chapters X-XIX) 

 in the order of their increasing complexity. Since there have already been 

 several chapters dealing with seed plants, the present one, whUe adding new 

 material, is also somewhat in the nature of a summary. 



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