90 MISC. PUBLICATION 101, U. S. DEPT. OF AGRICULTURE 
FicURB 23.—B.—Creosote bush (Covillea tridentata), enormously abundant in the 
Lower Sonoran Zone of the Southwest and perhaps the outstanding indicator 
of it. It is not palatable to livestock. A, An individual carpel or nutlet 
most wholly a minus quantity in the annual range forage crop, as 
livestock normally will not touch it under any circumstances, but 
the flower buds are edible when pickled. On the other hand, Grif- 
fiths (48, p. 69) reports that sheep are poisoned by it, the greatest 
