112 



COMPETITION AND CONSTANCY. 



flowers of all are variously blue or blue-purple in color, with the exception 

 of P. barbatus, in which they are vermilion. The flowers of P. glaber are 

 the largest, decreasing through unilateralis, glaucus, and halli to gracilis; 

 those of P. barbatus have a narrow tube as in the last, but they are much 

 longer. The secund clusters are most conspicuous in P. unilateralis and 

 P. glaber and the open few- flowered one of P. barbatus is the least so, in spite 

 of the brilliant flowers. The pink-purple corollas of Elephantella groen- 



Table 78. — Natural and bouquet competition of Chamaenerium, and Frasera. 



landica are individually inconspicuous, owing to the slender coiled tube, 

 but they are massed in a compact cluster that has a considerable degree of 

 visibility. The amount of both nectar and pollen is much less than in the 

 various species of Pentstemon. The flowers of Dodecatheon meadia are 

 bright pink and of about the size of the smaller pentstemons; usually but 

 one or two are in bloom in a cluster at the same time and the amount of 

 nectar and pollen is small. The other species concerned have been pre- 

 viously described (plates 7, 8, and 12). 



