40 AMERICAN FERN JOURNAL 
rock outcrops and mossy gneiss boulders of the shaded 
upper talus slopes; Filix bulbifera is found in two or 
three cool, well shaded situations at the foot of the 
talus; Asplenium pinnatifidum grows in earth pockets 
of the cliff at a single locality; Pteretis nodulosa occu- 
pies here and there considerable stretches of the shaded 
narrow belt of flood plain; and just above the last, 
especially at the mouth of the wooded ravines or “runs,” 
Athyrium pycnocarpon and A. thelypteroides are locally 
abundant. The more exposed rocks of the summit and 
upper slopes are often covered by Polypodium vulgare, 
and the moister, lower areas of the talus slopes every- 
where support large plants of Dryopteris marginalis. 
In one or two of the moist runs occur colonies of Dry- 
opteris Goldiana. Selaginella rupestris is found in sev- 
eral rocky, open situations near Great Falls, and with 
it Cheilanthes lanosa. A single colony of Aspleniwm 
montanum occurs here also. 
These records indicate very definitely the element 
of northern or mountain-loving species within the flora, 
and leave few additional species reasonably to be looked 
for, excepting Asplenium Bradleyi and Athyrium angus- 
tum. 
The Coastal Plain region, lying mainly east of Wash- 
ington proper and southward along the broad lower — 
Potomac past Alexandria to Mount Vernon and Mar- 
shall Hall, is low and more nearly level, with contours 
mostly gentle, marking broad open valleys. The soils 
are inclined to be strongly acid. Much of this terri 
tory, like that of the Piedmont, is under cultivation; 
but there are also wide stretches given over to poison 
Sumac and impassable cat-brier thickets, drained by = 
sluggish streams, which only the most enthusiastic 
collector will explore in Washington’s tropical dog- 
days, when the “jiggers” are at their worst. 
