THE TOUMEY CACTUS GARDEN. 



277 



tamarisk family; others have classed it with the phlox family, 

 the purslane family, the orpine family, and with the Frankeniacese. 



The native night-blooming cereus {C evens greggii) is also 

 worthy of brief mention. This 

 plant is quite unique among 

 cacti in that it develops some 

 distance underground a fleshy 

 root six to twelve inches in 

 diameter and two feet or less 

 in length, from which pro- 

 ceed one or more inconspicu- 

 ous, stick-like stems. Thus 

 Cereus greggii stores in un- 

 protected, subterranean struc- 

 tures what other cacti collect 

 in their spine-coated stems. 

 During the latter half of 

 June or the early part of July 

 the large cream-white flow- 

 ers, the handsomest and most 



fragrant among Arizona cactus flowers, open in the evening hours 

 and close shortly after sunrise. 



Other plants of special interest are the chollas or cylindro- 

 puntias and the biznagas or fish-hook cacti, the barrel-shaped 

 bodies of which almost without exception lean southward. These 

 plants are virtual reservoirs scattered here and there over the 

 arid mesas, from which the thirsting traveller may obtain water 

 in times of need. From the large fleshy interiors of these plants 

 is made the delicious cactus candy, the " cubierto " of the local 

 markets. 



Fig. 48. Biznaga, or barrel cactus, 

 cut across to show the thick, white, 

 water-bearing tissue. The small 

 center is the wood and pith. 



