114 RECOGNIZING AND CORRECTING DECLINING FORAGE 



perennial herbs. Many of these are entirely dependent upon 

 seed for their reproduction. 



(Forest Service, under direction oj tlie Author.) 



Fig. 32. — dominant PLANTS OF THE SECOND OR LATE WEED STAGE, SHOWING 



HABIT OF GROWTH. 



From left to right, blue foxglove [Penlslemon procerus), yarrow {Achillea lanulosa), and sweet sage 



(Artemisia discolor). Yarrow is the only one of the trio of any appreciable value as forage. 



Destruction of the Foxglove-Sweet Sage-Yarrow Cover. — 



Low peavine {Lathyrus leucanthus) , evening primrose (Lavauxia 

 flava), false cymopterus {Pseudocymopterus Tideslromii) , Mexi- 

 can dock {Rimiex Mexicanus), and tongue-leaved violet {Viola 

 linguaefolia) are the most reliable and characteristic indicators 

 of the gradual destruction of the more palatable second weed 

 stage cover. With the continued operation of the destructive 

 factors, these relatively short-hved perennials are soon replaced 

 by annual plants. 



