THE AMERICAN BOTANIST 37 



scandens, attractive not because of its inflorescence but on ac- 

 count of its pretty scarlet arils. The stems of this shrubby 

 climber here attain an unusual diameter. 



Yucca glaiica — "bear-grass" or "soap-weed" is a very in- 

 teresting xerophyte, or desert-dweller, with its handsome 

 leaves of fadeless green and its racemes of curious flowers. 

 Natural selection has given this plant a glacous foliage with a 

 hard epidermis, and in view of this character the evaporation 

 from the surfaces is very much diminished. The sword-shaped 

 leaves are spiny-pointed, and collectively they constitute a 

 chcval-de-frise which effectually repels the attempts of cattle 

 to nibble at them. But these animals are veiy fond of the 

 clusters of flowers which appear in spring above the rosettes 

 of leaves. Indeed, they wander for miles to procure these tid- 

 bits, and it seems strange that any capsules whatever have a 

 chance to mature, for after a little while we behold, all over 

 the prairies, but little of the flower-clusters besides their broken 

 stalks projecting above the assemblage of leaves. Old plains- 

 men and "bull-whackers" tell us that in former times the buf- 

 faloes were equally fond of the flowers, and there is no reason 

 for doubting the statement. Perhaps the bison whose skull 

 and "cross-bones" I discovered one day projecting from the 

 face of a bank beneath four feet of soil at the edge of the Bad 

 Lands had ventured too near the verge when reaching for a 

 bunch of the sweet, savory blossoms, and had been precipi- 

 tated to his death below — no one will ever know. What puz- 

 zles me is the question why natural selection has not been 

 driven to adopt some means to prevent the yucca's flowers 

 from being so generally devoured by herbivores. But no doubt 

 it is through sheer force of numbers that they survive and 

 multiply. 



A companion of the yucca in the sand-hills, and to a lesser 

 extent in some places near the Bad Lands, is the bush morn- 

 ing-glory {Ipomoea leptophylla) which, as its name indicates, 

 assumes an upright habit instead of the trailing one that the 



