8 AMERICAN FERN JOURNAL 
The ostrich fern, Pteretis nodulosa (formerly considered 
an Onoclea, then Matteucra) is best developed in alluvial 
soils and on damp limestone ledges, and its soil reaction 
does not vary much from neutrality. Near Lake Will- 
oughby, Vermont, a subalkaline reaction was observed 
once, but minimalkaline was the rule. Along the 
Potomac river in Virginia just northwest of the District 
of Columbia it grows in sand kept nearly neutral in 
reaction by frequent inundation by the calcareous river 
water, and it does not spread far into the more acid 
upper levels. In its occurrence in the mountains of 
West Virginia the soil is very slightly acid, and it is re- 
garded as a typical circumneutral soil plant. The 
sensitive fern, Onoclea sensibilis, is on the other hand a 
plant of wide reaction range. While not common in 
sphagnum swamps, it does grow in fairly acid soils; yet 
it seems to thrive just as well in limestone regions, where 
the waters are minimalkaline. It is accordingly placed 
in the indifferent class. 
The hay-scented fern, Dennstedtia punctilobula (once 
classed as a Dicksonia) does not appear to have any 
marked preferences as to soil reaction. It often grows 
in sandy woods, although there thriving best on slopes 
where soils of somewhat diminished acidity approach 
the surface. It has even been observed in mediacid 
peat in the Dismal Swamp, in southern Virginia. On 
the other hand it grows on limestone ledges and in leaf 
mold accumulated on other rocks, where minimalkaline 
reaction may develop, and is to be regarded as a typically 
indifferent species. 
The narrow-leaved chain fern, Woodwardia areolata 
(also known as W. angustifolia, and often placed in a 
different genus, Lorinseria) abounds in the New Jersey 
Pine Barrens, in sandy swamps east of the District of 
Columbia, in the Dismal Swamp, ete., where the reac- — 
tion is almost uniformly mediacid. The same reaction 
