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FRANCIS RAMALEY 
(b) Carex rossii Grassland Association. — -This community appears in 
clearings and burned areas of coniferous forest on exposed hillsides of the 
montane and subalpine zones. The plants of Carex rossii form dense mats 
from I dm. to i m. across, developing in sandy or gravelly soil especially on 
south and west exposures. Subordinate plants of the Carex rossii grass- 
land are Vaccinium caespitosum, Thermopsis divaricarpa, Chamaenerion 
spicatum, Carex siccata, Ruhus melanolasius, and various forest plants in 
small numbers. There are some lichens on the ground, especially species 
of Cladonia and Peltigera under stones or old logs. This association may 
give way soon to coniferous forest, since seedlings of Pinus flexilis and Pinus 
murrayana are likely to develop. When the new forest is well started the 
Carex has all but disappeared, it being intolerant of shade. In some situ- 
ations, however, the reproduction of pines is poor, and it may be many 
decades or even centuries before the Carex grassland gives way to forest. 
{c) Carex siccata Grassland Association. — This and the preceding com- 
munity might be classed by some students as consociations, but to the writer 
they seem so different as to demand associational standing. Carex siccata 
spreads by rhizomes and forms a loose sod; it does not produce dense mats 
at all. Carex siccata is more likely to appear at higher altitudes. It is 
more tolerant of shade and less xerophytic than C. rossii. The associated 
plants with C. siccata are those already mentioned for the C. rossii grassland 
with some additions such as Tessaranthium stenopetalum, Koeleria gracilis, 
Amarella plebeja, Sambucus (scattered), etc. The Carex siccata grassland 
is often a temporary climax having a long period of existence. Frequently 
occurring near timberline where the establishment of tree seedlings is diffi- 
cult at best, the Carex occupies the soil and may maintain itself for centu- 
ries without invasion. 
(d) Carex elynoides Grassland Association. — This community is found 
on mountain tops and slopes in the alpine zone or occasionally at lower ele- 
vations. Unlike the two associations just named, this one does not develop 
so often on steep slopes with poor soil but on more nearly level ground where 
humus may accumulate. It is not, however, to be considered as meso- 
phytic, differing markedly as it does from the hydrarch alpine meadow. 
Soil is drier and the vegetation cover is not so close. Carex elynoides is a 
densely cespitose species and will be best understood if described as the 
alpine form of C. filifolia. It occupies from 40 to 80 percent of the soil 
surface. Associated plants are partly xerophytes, as Selaginella densa, 
Silene acaulis, Oreoxis alpina, Festuca minutiflora, and Tetraneuris lanigera, 
and partly mesophytes, as Trifolium dasyphyllum, Acomastylis turbinata, 
Rydbergia grandiflora, and Castilleja occidentalis. This mingling of xero- 
phytic and mesophytic forms is common everywhere in high altitudes be- 
cause of the great diversity of soil depth and soil moisture in even a small 
area, presence of large rocks, and other disturbing factors. Carex elynoides 
grassland will probably become in time alpine meadow, but perhaps it will 
