32 ANIMAL LIFE OF CARLSBAD CAVERN 



canyons and gulches, where it is conspicuous by reason 

 of its graceful form, beautiful flowers, and light-colored 

 spineless branches. Unarmed and seemingly unpro- 

 tected, it is not generally eaten by stock and evidently 

 proves unpalatable or unwholesome. 



The gray shadscale (Atriplex canescens) would be an 

 abundant shrub over the desert if armed as fully as 

 many more fortunate plants. With fleshy, edible 

 leaves and twigs and no real spines for protection, it 

 leads a precarious existence and is crowded to nooks 

 and corners on the cliffs and along the sides of steep 

 banks, or hides under the wings of some thorny shrubs 

 or cactuses where a few plants can mature their four- 

 winged seeds and keep the species alive. No small 

 part of the value of thorny plants is their protection of 

 such weaker neighbors. 



The well known grease-brush (Sarcobatus vermicula- 

 tus) thrives where the soil is so impregnated with soda, 

 gypsum, lime, and salt, that few other plants can 

 compete with it. On many of the "alkali" flats it is 

 the dominant shrub, growing in a clear stand over ex- 

 tensive areas, its light green and fleshy leaves testifying 

 to ample moisture and rich plant food. The leaves and 

 twigs, although strongly flavored with salt and soda, are 

 eaten by stock while fresh and green, but the myriad 

 twigs quickly harden into stout thorns that protect 

 the plants from complete destruction. 



The cliff rose, poniel, or Apache plume (Fallugia 

 paradoxa), with large, white flowers and powder puffs 

 of plumy seeds, is thornless and edible, and is so exten- 

 sively eaten by stock that few plants remain in the cave 



