CLEMENTS 



PLATE 78 _ ,. 



A. A summer annual, Euphorbia marginatn, inilic-atiu};; coniplL-lc oviTuraziag m a i):ujture, 



Fountain, Colorado. 



B. A winter annual, EschicholUia mexicana, Indicating both overgraiing of grasses and 



grazing capacity, Santa Rita Reserve, Tucson, Arizona. 



