66 PRETZ: FLorRA OF LEHIGH CouNTY, PENNSYLVANIA 
Saucon Creek, 144 mile northeast of Lanark, November 5, 1910, 
3973. 
DRYOPTERIS MARGINALIS (L.) A. Gray 
General throughout, on all soils and formations and in many 
situations. Frequently abundant. Often in niches and fissures 
on outcrops. Frequently a roadside species in the vicinity of 
woods. Fronds 8.9 dm. (2.9+6) long and 2.8 dm. wide represent 
average luxuriance. Collected with ripe fruit on July 4. Ever- 
green but mostly prostrate by November. Variable. 
DRYOPTERIS NOVEBORACENSIS (L.) A. Gray 
General throughout, but most abundant onthe South Moun- 
tains, where the species sometimes occupies areas of limited extent 
in almost pure association in the rich woods. Fronds 5.7 dm. 
(0.8+-4.9) long and 1.5 dm. wide represent maximum luxuriance. 
Fruits in July. Herbaceous, withering early. 
DRYOPTERIS SPINULOSA (Miill.) Kuntze 
General throughout, associated with D. intermedia. Most 
abundant on the South Mountains, where it occurs in association 
with D. intermedia, but never even approaches this species in 
abundance. In general not nearly as luxuriant as the latter species. 
Collected in fruit on June 14. Tender, evergreen, mostly turning 
yellow early, but some fronds lasting well toward winter. 
This and D. intermedia are very variable and, approaching 
each other closely, offer great difficulty in identification. Dr. 
Dowell has collected forms (general vicinity of bog 1 mile south 
by southwest of Mountainville, August 25, 1907, Dowell 5112) 
that are undoubtedly hybrids. These specimens, and material 
apparently identical with them in the writer’s herbarium (803), 
have been referred here. Material from along the Kittatinny 
Mountains in the vicinity of Bake-oven Knob (June 21, 1908, 
12846) has also been referred here. This intergrading of the species 
probably affects the comparative hardiness of the species, an as- 
sociated character well marked in typical forms. 
DrYopTERIS THELYPTERIS (L.) A. Gray 
General throughout. May be expected usually in abundance 
in all marshy meadows throughout and in favorable habitats 
