LAKE-SHORE VEGETATION IN NORTH-CENTRAL COLORADO 67 
the two associations are mingled, or it may be entirely lacking. In the 
latter case the belt of heath may follow abruptly after sedge moor or rush 
moor or meadow moor. It may be, in turn, followed on higher ground 
by forest, or there may be an intervening strip of meadow. Heath may 
occur in scattered patches on elevated areas of the sedge moor, probably 
most often in shallow soil over large rocks. A quadrat record (table 8) 
taken in a part of the heath which is not differentiated into consociations 
gives an idea of the floristic composition. 
Table 8. Meter quadrat in subalpine heath association at North Forest Lake 
{altitude 10,800 ft.) in Gilpin County, Colorado, August 17, ipi8. 
The figures indicate percentages of ground covered 
Bare ground and rocks 20 
Gaultheria humifusa 25 
Vaccinium caespitosum 18 
Kalmia micro phylla 15 
Erigeron salsuginosus 7 
Carex festivella et spp 5 
Ligusticum tenuifolium 4 
J uncus Drummondii 2 
A grostis humilis 2 
Lichens 2 
100 
The Kalmia heath consociation is characterized by the low shrub Kalmia 
microphylla, about 2 dm. tall. This is often only scantily distributed, but 
sometimes it forms a clearly-marked though narrow belt of vegetation part 
way around the moor. The writer has, in no case, seen a complete circum- 
area of this plant. 
The Gaultheria heath consociation seems to develop often on shallow soil. 
In it dense patches of Gaultheria humifusa occur. The plant is a depressed 
undershrub only a few centimeters high. Subordinate species are Vac- 
cinium caespitosum, Muhlenhergia filiformis, Erigeron salsuginosus, Hie- 
racium gracile. Almost any meadow plant may occasionally be present. 
The meadow association is conspicuous because of the large and brightly- 
colored flowers of some of the abundant species. It would be possible to 
name six or more societies of local or infrequent occurrence distinguished 
by floristic differences, but in the present paper it will be best merely to 
characterize two consociations. These, as already indicated in table 5, 
may be called the Erigeron-Castilleja-Ligusticum consociation and the 
Pedicularis-Vaccinium consociation. They are rather constant in occur- 
rence, the first named being next to the heath (or to sedge moor or rush 
moor or meadow moor in some cases), the second merging into the under- 
growth of the forest. There may be considerable bare ground (10 to 40 
percent). Many species characteristic of lake-shore meadows in the mon- 
tane zone (10, 11) are absent, as Fragaria glauca, Tium alpinum, Potentilla 
pulcherrima, Erigeron macranthus. 
