THE AMERICAN BOTANIST. 105 



and in a few short hours after a storm, the earth is dry again. 

 These arid conditions have a very noticeable effect upon the 

 few other species that here and there struggle with the pines 

 and oaks for existence. For the most part they are heaths 

 or heath-like plants with thick leathery leaves that are slow 

 to let their scanty supply of moisture go. The wintergreen 

 and trailing arbutus are common as is their near relative the 

 bearberry. This latter is a prostrate shrub with small shining 

 leaves and a profusion of red berries, very attractive to the 

 sight, but containing a juiceless mealy pulp within. Appar- 

 ently these berries once had juice, but the plant long ago gave 

 up the idea of acquiring enough water in such a place to pro- 

 vide them with it. The cactus is the only green thing in the 

 region that seems absolutely happy even in the driest weather. 

 Its thick stems act as so many reservoirs storing up water 

 during wet weather against a time of need and parting with 

 it very grudgingly in dry times. This is probably the only 

 plant that can produce juicy fruit no matter how dry the 

 season. In June and July the plants are fairly full of the dark 

 red "prickly pears." 



It is sometimes difficult to understand how certain species 

 of sand plants are able to exist at all until the underground 

 portions are examined. It is then seen that the top is but an 

 insignificant part of the whole plant, the thick roots often 

 descending straight down for a distance of nearly six feet in 

 their search for water. A notable exception to this is a spe- 

 cies of "reindeer moss," a gray wiry lichen which forms little 

 rounded knolls like pincushions on the bare sand. It lies loose- 

 ly on the earth and appears not to be attached to i'; at all. At 

 mid-day it is seemingly dead and the stiff branches crunch 

 under foot, but as soon as the dew begins to fall it revives 

 and at once becomes moist, pliant, soft as velvet and full of 



life. 



Desolate and barren as the pines ordinarily appear the 

 extreme is not reached until one has seen the tract of land 



