184 BOTANICAL GAZETTE [SEPTEMBER 
Schwein., Ribes aureum Pursh, Clematis ligusticifolia Nutt., Symphoricarpos 
occidentalis Hook., Rhus trilobata Nutt. : 
In an earlier stage this formation is found best developed in 
the irrigated meadows where Poa pratensis L., Eragrostis alba L., 
Juncus balticus Willd., Heleocharis palustris (L.) R. & S., and 
Medicago sativa L. may rank as facies. 
~* ~ . “ ‘ ; 4st the Routelou4 
Fig. 10.—Floor of the pine formation (P. scopulorum) covered with the Boute! 
formation (B. oligostachya, Koeleria cristata, and Artemisia canadensis). 
Xanthium commune and Melilotus alba are among the very a 
plants to enter on a newly formed ditch bank. In this formation 
are found many of the common species which occur in mesophyti¢ 
situations in the eastern part of the United States. 
PINE FORMATIONS. 
. 2 - formations 
As CLEMENTS? has pointed out, there are two pine format | 
ang 
near the base of the mountain range, the “foothill woodland 
2 Univ. Neb. Studies 4: no. 4. 1904. 
