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UNIVERSITY OF COLORADO STUDIES 



Currants. Ribes longiflorum Nutt.; R. pumilum Nutt.; R.vallicola 

 Greene. — The several species grow most abundantly in the gulches. 

 Scattered bushes of Ribes pumilum are found on the north slope and 

 in the shade of the pines growing on the north crest of the mesa where, 



Fig. 4. — Choke Cherry. Prunus melanocarpa (A. Nels.) Rydb. — The map indi- 

 cates that this tree is generally distributed in the gulches. A younger growth occurs in 

 clumps in the depressions, amphitheaters and ravines on both sides of the mesa. In 

 these situations it is found below the hill crest in the seepage zone. (See Fig. 2, p. 14). 

 Isolated trees, one or two years old, occur even in dry and exposed situations. It is prob- 

 able that these trees started during a series of wet years and were able in that time to de- 

 velop a root system deep enough to enable them to get the required moisture from 

 the soil. 



along with thimble berries, they form small thickets. It is common to 

 find this same species around almost every large pine tree and large 



