plants which grow there, I called this problemto the attention of Paul J. St, Amant, 
supervisor of the Shawnee National Forest, He asked Donald Dorn, a federal forest- 
er who was studying the Shawnee Forest as a possible recreation and scenic area, 
to visit Jackson Hollow with me and to make recommendations for the preservation 
of these rare plants, 
On December 9, 1959, Mr. Dorn, Mr, Clark, andI visited the large stand 
of filmy fern in the north section of Jackson Hollow, Mr, Dorn was surprised at the 
amount of the fern in this overhang. The three of us were more surprised at the 
brilliant sunlight which penetrated the overhang on that clear December morning, 
We observed that at 10 A. M, the ferns were bathed in sunlight. We surmised that 
at this time of year some of the ferns may receive up to 2 hours of direct sunlight. 
Doubtless this is not the case in the spring and summer months, In those months 
the foliage forms a fairly dense canopy over the soil and shades the adjacent cliffs; 
also, in those months the position of the sun and the consequent angle at which its 
rays strike the overhang would make it impossible for the direct rays to reach the 
ferns, Apparently brilliant sunlight during the cold months of the year does not re- 
tard the growth of the fern. The amount and type of light that reaches the base of 
the overhang during the course of the daylight hours and through the seasons would 
make a very interesting study. 
We left Jackson Hollow and drove to Hayes Creek Canyon, where we visited 
the two stations of filmy fern in that area, fig. 2, locality 12. The amount of fern 
we observed in the first station was about the same as that which Mr, Clark andI 
observed in 1957, fig. 3. In the secondstation we found that the fern was apparently 
on the decline; the fronds were very small in size and few in number, 
Some daylight remained, and we decided toexamine the escarpment of Pounds 
sandstone 2 miles south of Ozark in Johnson County, fig. 2, locality 1. The ele- 
vation of this escarpment is between 440 and 480 feet above sea level, As we were 
examining one ofthe overhangs, Mr, Clark discovered several patches of filmy fern, 
the first tobe found in Johnson County, One patch, whichcontained plants with small, 
scattered fronds, covered an area of approximately 9 square feet, Higher up the 
cliff in a small niche another group of ferns grew in patches that measured 8 by 10 
and 3 by 4 inches, Mr. Clark photographed the site, fig. 13, and Icollected a sample 
for the Illinois Natural History Survey herbarium, This station, the ninth inthe state, 
was the first in a county other than Pope. It is approximately 2.5 miles by air from 
the nearest Pope County site, the north section of Jackson Hollow, 
How long the filmy fern will grow in the Johnson County site is conjectural, 
Much of the forest adjacent to the base of the escarpment had recently been cut, It 
appeared to Mr, Dorn, Mr, Clark, and me that this cliff, with an east-facing ex- 
posure, will be exposed in the mornings to the direct rays of the hot summer sun, 
This exposure, perhaps, will make it impossible for the filmy fern to survive, 
In order to bring the information on the collections of filmy fern in Illinois 
up to date, the following records, which represent specimens in the herbarium of 
the Illinois Natural History Survey (ILLS), should be added to those cited by Mohlen- 
brock & Voigt (1959): 
JOHNSON COUNTY: On sandstone, Ozark Creek, 2 miles southof Ozark, De- 
cember 9, 1959, R. A. Evers 63236, POPE COUNTY: On sandstone, Hayes Creek 
Canyon, north of Eddyville, October 23, 1957, R. A. Evers 55741; February 26, 
1958, R. A. Evers 55831 (duplicate in herbarium of Illinois State Museum, Spring- 
13 
