northward, is rare or wanting below this in the Valley. Near 
Judge Parker’s estate at Esopus is an island, without name, 
upon which occur the most southerly specimens of the arbor 
vitae ( Thuja occidentalis ) in the Aqueduct region. Near Piermont, 
just below Nyack, are large quantities of marsh fleabane ( Pluchea 
ca?npho7-ata ) , on what are locally called the “Flats”. This plant is 
obviously an intruder from the salt marshes of the Long Island 
and New Jersey coasts. 
Scores more of these exceptions could be cited to prove the 
general rule that the flora of the Catskill Aqueduct region is of 
two types. It is true that they intergrade somewhat, but on the 
whole the Highlands seem to act as a barrier to many of our wild 
plants, particularly to the mountain species, some of which have 
never been known to occur in the valley south of Storm King or 
Anthony’s Nose. It is through the former that the aqueduct 
takes the great plunge under the Hudson to the east bank of the 
river. 
THE MOUNTAIN PLANTS 
No real alpine conditions are found in the Catskills, the high- 
est peak being scarcely over 4,000 feet. But there are many peaks 
that are over 2,000 feet, and toward the summit of these, and on 
the top of Slide Mountain, there occurs agroup of plants that are 
found practically nowhere else in the Aqueduct tract. Some of 
the more conspicuous of them are: 
Braun’s Polystichum (Polystichum Braunii ) , a strong growing 
fern, growing in rocky woods. 
Balsam Fir (Abies balsa?nea ) , the tree of fragrant memory, 
common enough near the head-waters of Esopus Creek, un- 
known in the low-lands. 
Wood Reed Grass (Cinna lalifotia); besides the Catskills it 
has been found at Pine Plains, Dutchess county. 
Several species of sedge, which are plants with the general 
aspect of grass, notably Carex novae-angliae. 
Mountain Yellow-eyed Grass (Xyris mo?ita?ia ) , known only 
from the highest regions of the Catskills, in our area. 
Mountain Strawberry ( Fragaria canadensis ) , and its relative 
Fragaria terra-Tiovae, both isolated on the highest peaks in the 
watershed of theAshokan Reservoir. 
Mountain Ash (Pyrns sitche7isis ) , differing from the common 
mountain ash in its short-pointed leaves. The latter is common 
in many places in the valley, but P. sitchensis is found only at the 
highest elevations. 
Violet ( Viola Selkirkii ) , known, in the Catskill region, only 
from near mountain summits, and usually only above 2,500 feet 
where another species, peculiar to high elevations, Viola renifolia, 
is also found. 
One-flowered Wintergreen (Mo7ieses 7miflora), with small 
white flowers in June. Found in the Adirondacks and nearly to 
