IOWA ACADEMY OF SCIENCE. 
1.05 
PERNS AND LIVERWORTS OP GRINNELL AND VICINITY. 
BY HENRY S. CONARD. 
The flora of the high prairie is peculiarly devoid of mosses and ferns. Ex- 
cessive insolation and evaporation are prime causes of this. Though the 
necessary protection for mosses might be afforded by the tall grasses, the 
ground is too closely occupied, and moisture throughout much of the year is 
too scant. 
Of ferns we find in the vicinity of Grinnell (including a radius of four miles) : 
1. Botrychium virginianum L (Sw\). 
2. Osmunda claytoniana L. 
3. Adiantum pedatum L. 
4. Asplenium felix-foemina (L) Bernh. 
5. Cystopteris fragilis (L) Bernh. 
6. Onoclea sensibilis L. 
Only Cystopteris can be considered a plant of the high prairie. It occurs 
on porus soils of the Marshall loam type, consisting of glacial drift. Here 
the vegetation is much less dense than on the fine grained loessial Marshall 
silt-loams. 
In slight depressions where there is some seepage of water throughout the 
year (except in especially dry seasons), Onoclea occasionally appears. These 
places are the heads of the branches of the smaller streams. In the two lo- 
calities of this kind within our range, Populus tramuloides, that pioneer tree, 
is found nearby. These depressions, from their size and position, are to be 
regarded as among our most recent topographic features. 
The other four species occur only in well-wooded districts, over the line in 
Jasper County. They are denizens of the loose sweet humus of the forest. 
Osmunda, how^ever, usually prefers a substratum of yellow clay. These species 
have doubtless ascended the river valleys along with the principal trees. We 
have therefore but one Prairie Pern. ^ 
In cultivation in Grinnell the above named Osmunda, Asplenium and Cystop- 
teris prosper when planted on the north side of houses, close to the foundation, 
or on west or east sides where there is shade. Under the Aspleniums we 
usually find numerous prothalli in autumn, but the species does not spread 
successfully. Cystopteris spreads much more, even tending to wander out into 
grassy and more or less sunny places. 
Onoclea struthiopteris was introduced last year (1911) into the Botanic Gar- 
den of Grinnell College, and is growing nicely at this time (April 25, 1912). 
The plants came from a private garden in Mason City, Iowa. 
The liverworts are not found at all on the high prairies in this locality.* The 
nearest occurrence is that of Aneura pinguis oh a clayey bank at Arbor Lake. 
This “lake” is an artificial pond in the southwest part of Grinnell City. Aneura 
grew at the foot of a slope facing north, where seepage water supplied constant 
*Marchantia occurs occasionally in shaded lawns in Grinnell. 
