20 AMERICAN FERN JOURNAL 
FEATURES OF INDIVIDUAL SPECIES 
Cheilanthes lanosa (vestita) is recorded in the litera- 
ture as growing on sandstone, shale, schist, and trap 
rocks, and the writer has found it on the first three of 
these in Maryland, Virginia, and West Virginia. In 
these occurrences the soils have proved to be dominantly 
subacid to minimacid in reaction. In what appears to 
be the only recorded occurrence of this fern in a lime- 
stone region, that at Natural Bridge station, Virginia, 
it grows in clayey soil on a steep bank; and tests of this 
soil, for a specimen of which the writer is indebted 
to Mr. John P. Young. of Washington, D. C., have 
shown it to be neutral, any free calcium carbonate which 
may have been present having been leached out by the 
rain. This fern is therefore regarded as an acid soil 
plant showing a considerable degree of tolerance for 
calcium compounds. 
It seemed a matter of interest to ascertain if other 
species of the above genus showed similar soil require- 
ments, but no opportunity to study any others in the 
field presented itself. Accordingly tests were made on 
the soil adhering to the roots of specimens of Cheilanthes 
tomentosa in the U. 8. National Herbarium, for which 
privilege—as well as for other valuable assistance in the 
preparation of this paper—the writer is indebted to 
Mr. William R. Maxon. In specimens from Paint Rock, 
North Carolina, where the rock is presumably, as usual 
for this fern, sandstone, the reaction proved to be sub- 
acid. In one from Natural Bridge Station, the locality 
referred to in the preceding paragraph—the reaction was 
low minimacid. This species is therefore also classed 
provisionally as an acid soil plant tolerant of calcium. 
Pellaea atropurpurea, as observed in Pennsylvania and 
adjoining states, is found not only on limestone, but also 
on apparently noncalcareous sandstone, schist, shale, 
