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ILLINOIS ACADEMY OF SCIENCE 



true that many of the species are different but the same genera 

 are present, and, what is more important, the ecological types 

 are the same and the association occupies the same place in 

 the succession. 



In the Colorado parks this is often one of the most extensive 

 associations in its extent and apparently is of rather pro- 

 longed duration. Several undetermined mosses are rather 

 abundant upon the soil, but the initial and most abundant seed 

 plant is Carex utriculata, soon mixed with C. variabilis, C. 

 lanuginosa, Eleocharis tenuis, and such herbs as Caltha ro- 

 tundifolia, Sedum rodanthum, Montia chamissonis and Spir- 

 anthes stricta. As soil formation advances and the drainage 

 gradually develops, bringing the soil surface well above the 

 ordinary water table, the change is marked by the invasion 

 of Carex f estiva, and many of the grasses of the succeeding 

 grassland. It is, however, a noticeable feature of the grass- 

 land that many of the pioneers of the sedgeswamp persist in 

 the meadow, a condition not uncommon also in the low prairie 

 of Illinois. 



Following the sedges is the main grassland community, 

 termed the meadow association in the mountains, but cor- 

 responding directly with the prairie grassland of Illinois. In 

 aspect the two agree closely, the bulk of vegetation being rath- 

 er coarse grasses mingled with many herbaceous plants of 

 other habits of growth. In both the other herbs outnumber 

 the grasses in species, the mountain grassland abounding in 

 species of Eriogonum, Cerastium, Thalictrum, Potentilla, 

 Geum, Epilobium, Gentiana, Pentstemon, Galium, Astragalus, 

 Carduus, Senecio and Erigeron. In many parts of the grass- 

 lands the limits of this meadow association may be determined 

 by the distribution of Erigeron vtacranthus, a species that 

 seems to be a certain indicator of the degree of mesophytism 

 characteristic of this meadow. From the evidence at present 

 available it is impossible to decide whether such a meadow is 

 the true climax of these mountain parks, but it is certain that it 

 persists for long periods and occupies the most mesophytic 

 habitats outside the forests. In it the soil has the best develop- 

 ment of humus and possesses the best water supply and in it 

 is seen the greatest luxuriance of plant life, including a con- 

 siderable number of species from the associations immediately 

 above and below it. From the sedge-moor come Carex f estiva 

 and C. variabilis, Calamagrostis canadensis, Deschampsia flex- 

 uosa, Koeleria cristata and Beckmannia erucaeformis, while 

 among the more mesophytic of the dry-grass species which 

 intrude, are Stipa comata, Festuca pseudovina and several of 



