PRETz: FLORA OF LEHIGH COUNTY, PENNSYLVANIA 71 
Collected with ripe fruit on August 1. Herbaceous, withering 
early. 
Forms occur in the bogs or along the streams on the South 
Mountains which simulate closely the characters of P. Phegopteris. 
It has been suggested that farther south the species intergrade, and 
perhaps some such forms exist here. 
PHEGOPTERIS PHEGOPTERIS (L.) Underw. 
General and often abundant on the moist shale cliffs along the 
Lehigh River from Cementon to near Slatington. Laurel Hill, 
1878, Krout; Cementon, July 11, 1908, 1325; Rockdale, August 15, 
1908, 1468. Fronds 3.9 dm. (2.6+1.3) long and 1 dm. wide are 
rather below average though ‘the fronds are never very large. 
Collected with ripe fruit on July 11. Herbaceous, withering early. 
POLYPODIUM VULGARE L. 
Frequent throughout, on outcrops of all formations. It has 
been found growing in the cleft trunks of trees and occasionally 
on loose talus. Less abundant on limestone but on rocks in the 
mountains, and especially on the shale outcrops it is often very 
abundant, not infrequently in pure association. Varies greatly in 
size according to situation. Most luxuriant in rich leaf mold on 
the shelves of outcrops, and in such situations frequently 3.4 dm. 
(1.2+2.2) long and 7 cm. wide, which represents average luxuri- 
ance. Fruits in summer, is evergreen and may be collected well 
into winter, when severe cold causes the fronds to roll up to de- 
crease radiation. In general constant to type but with variations 
probably referable to certain described forms or varieties. 
POLYSTICHUM ACROSTICHOIDES (Michx.) Schott 
Frequent throughout, on all soils and formations and in all 
situations, but most abundant in moist (not wet), often rocky 
situations on wooded hillsides and along small streams, and in the 
vicinity of shaded bogs in woods. Also a frequent roadside 
speciesin the vicinity of woods. Fertile fronds 7.9 dm. (2.6+ 5-3) 
long and 1.2 dm. wide have been collected and represent average 
luxuriance. Fruits in July. Evergreen but prostrate in Novem- 
ber when the fertile portion of the frond is usually withered. The 
