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the best having but a small rainfall, have a vegetation all their 

 own, and the plants which go to make this up are provided with 

 various means by which they can live through these long dry 

 spells. Plants as ordinarily constructed could not survive the 

 extreme conditions which the desert plant is called upon to meet. 

 The perpetuity of such species is insured in a number of ways. 

 In the first place, a great many of the desert plants are annuals, 

 that is, the plant dies, root and stem, after completing its life 

 cycle, depending for the continuance of its kind upon seeds, 

 which it usually makes in great abundance. These seeds lie 

 dormant in the ground until favorable seasons of moisture arrive, 

 when they germinate and make the desert look like a flower 

 garden. This method, of course, is not peculiar to desert plants, 

 but it is one means by which they are perpetuated. 



It is, however, among the perennial plants, those which live 

 for several years, that the adaptive methods which make up the 

 characteristics of the desert plants and give to many of them their 

 odd and queer forms are most conspicuous. A glance at this 

 collection of plants in the conservatory court will show how 

 different from most plants they appear. Various methods are 

 resorted to in order to accomplish the same essential end, the 







Soi 



the base, as in the hua- 

 iqui, Ibervillea Sonorae, of Sonora. A specimen of this queer 

 lember of the watermelon family will be found in house no. 6 

 .f the conservatories. These large bodies lie around in the desert 

 ike large knots of wood, with apparently no life in them, but 

 dien the rains come they start into growth and send up long 

 ;reen stems which blossom and bear fruit. When the fruit is 

 nature, the stems die down and the plant assumes its dormant 

 :ondition until the next rainy season. In some cases, as in 

 ertain cacti, tubers are made in the ground, which serve the 

 ame purpose. In others, the stems and branches, or both, are 

 enlarged and fleshy, and serve as storage organs. This latter 

 :ondition is found largely in the cactus family. In the hedge- 

 zactus, it is the stem that is greatly enlarged, 

 .ften forming globose or cylindric bodies, a foot or more through 



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