FLOWERS OF HIGH ALTITUDES 93 



in late July in some shaded nook on a creek bank. 

 Then, as the water recedes into a narrow channel 

 and exposes a rocky bed along its course, as all Cali- 

 fornia streams do in summer, Pink Mimulus springs 

 up overnight among the newly uncovered rocks. Of 

 course, there must be soil among the stones, rich 

 surface soil brought down by the stream and depos- 

 ited in the sluggish turn; the water is probably near 

 the undersurface; the Sierran sun pouring on the 

 bare boulders raises the temperature; so it really 

 is an ideal forcing bed for Pink Mimulus; but the 

 place looks so barren and she looks so delicate that 

 you doubt your eyes and have to reason out the con- 

 ditions that make it possible for her to thrive there. 

 Thrive there she does and increases her race. Even 

 after the late September frosts, even until the Octo- 

 ber snows, you can pick some Pink Mimulus on the 

 emerged creek bed ; and the more you pick, the more 

 she rushes out to fulfill her duty before winter over- 

 takes her. 



The calyx of Pink Mimulus is said to be pris- 

 matic because it has five flat faces joined together 

 by five angles. Each 'face terminates in a tooth 

 pointing upward. The calyx remains on after the 

 corolla falls away. The calyx, as well as the stem 

 and leaf, are furnished with little hairs to keep the 

 plant warm. 



The lovely corolla is in two lips, not very differ- 



