62 THE AMERICAN BOTANIST. 



ly although not massed closely together. At a distance it ap- 

 pears globular in form resembling the tumble weeds in this 

 particular. A closer examination reveals a plant about two feet 

 high on an average with a root all out of proportion to its size. 

 Numerous slender stems spring from the crown. These stems 

 branch somewhat and are covered with patches of very small 

 leaves. Some species are shrubby, others herbaceous. Its 

 inflorescence is inconspicuous. It is a plant which seems to 

 hold a title of preemption which others dare not gainsay. 



So far I have failed to say much concerning its "boon 

 companion." But wherever you find the sage brush you are 

 also certain to find a clump of cacti of the genus Opnntia and 

 and sometimes manv others of dififerent o-enera. 



The Opuniias, commonly called prickly pears, are always 

 interesting especially when a close acquaintance is made unex- 

 pectedly. These attempts at friendship soon teach the animals 

 that roam the prairies that any undue curiosity or familiarity 

 is not desired. These prairie denizens soon understand and 

 give a tract of land containing the cacti a wide berth. 



The species of this genus are many and are characterized 

 by very succulent and much branched stems shaped not unlike 

 a pear in outline. These stems are used for storing up of the 

 moisture thus dififering from the sage brush which uses its 

 roots for that purpose. These stems are so protected that the 

 moisture is given little chance to evaporate. The innumerable 

 spines and prickles scattered over the surface and the tough, 

 thick and impervious skin incasing the stems arrest the dessi- 

 cating power of the sun. 



So succulent are the stems that they are in great demand 

 by gazing animals and would be heartily eaten were it not for 

 the little forts of tireless watchers wdiose reminders are not 

 readily forgotten. Various methods are adapted for removing 

 these prickles after which the plant makes an excellent and op- 

 portune food for sheep and cattle in seasons of prolonged 

 drouth. Man too sometimes has recourse to them to quench 



