1917] 
Poa Fendleriana 
Agropyron Smithii 
Elymus triticoides 
Leucocrinum montanum 
Calochortus Gunnisonii 
Yucca glauca 
Zygadenus intermedius 
Comandra pallida 
Allionia linearis et spp. 
Pulsatilla hirsutissima 
Argemone intermedia 
Corydalis aurea 
Draba spp. 
Erysimum asperum 
Potentilla spp. 
Astragalus spp. 
soralea tenuiflora 
Malvastrum coccineum 
Viola Nuttallii 
VESTAL—FOOTHILLS VEGETATION 
Onosmodium occidentale 
Pentstemon humilis et spp. 
Castilleja integra et spp. 
Campanula rotundifolia 
Liatris punctata 
Grindelia squarrosa 
Chrysopsis spp. 
Solidago spp. 
Aster spp. 
Machaeranthera aspera et spp. 
Erigeron spp. 
Ratibida columnaris 
Helianthus spp. 
Hymenopappus filifolius 
Hymenoxys floribunda 
Artemisia aromatica 
Artemisia canadensis 
Senecio plattensis et spp. 
Senecio spartioides 
375 
Mentzelia spp. Nothocalais cuspidata 
As regards distribution of the mixed grassland association in the foothills, 
it may be said that the primitive grassland is more frequent and occupies areas 
of greater extent, because of the general instability and rocky character of the 
sloping surfaces. In the upper foothills mixed grassland is absent from com- 
pacted soil level or rolling surfaces generally occupied by pine and Arcto- 
staphylos, etc., but dominates on the more exposed mountain sides, which are 
treeless. The mixed grassland, like primitive grassland, is subject to a gradual 
ecological and floristic variation, from the south northward, and from the short- 
grass of the plains to the montane dry grassland of elevations from 8500 to 
10,000 ft. 
BUNCH-GRASS ASSOCIATION 
CLeMENTs (1, p. 6), Andropogon, etc.; SCHNEIDER (21), half gravel slide 
formation, in part; SHANTZ (22, p. 43), Bouteloua hirsuta uta consocies, with 
Andropogon spp., Atheropogon, etc.; VESTAL (24, pp. 3 388-390), bunch-grass 
association: photograph and citation to descriptions in other regions; WATSON 
(25, p. 209), Andropogon, etc. 
The bunch-grass vegetation of the foothills is quite similar to 
that of the mountain-front and over the whole prairie region, 
including most of the same species, but containing in addition other 
grasses of similar growth-form but of different geographic distribu- 
tion. With the bunch-grasses are many composites and other 
