FERNS OF GREENE Co., Missourtr 45 
flora of Greene County does exhibit an interesting mix- 
ture of certain eastern, western, and southern elements, 
as might well be expected from its geographic position. 
This is not as well shown, however, by the ferns as by 
the flowering plants; nor do the former include more than 
one or two particularly interesting species. The phan- 
erogamic flora consists chiefly of typically eastern plants 
which extend to the Atlantic coast, some of them being 
here near the western limit of their range, such as Hydras- 
tis canadensis, Caulophyllum thalictroides, Bicuculla cuc- 
ullaria, Spiraea alba, Micranthes virginiensis, Rhexia 
virginica, Erigenia bulbosa, and Cynoxylum floridum. 
Associated with the eastern plants are many that are 
southern or western in their distribution, like Callirrhoe 
digitata, Cissus ampelopsis, Psoralea pedunculata and 
P. tenuiflora, Kneiffia linifolia, Megapterium missouriense, 
Mentzelia oligosperma, Ambrosia psilostachya, Bumelia 
lycioides, Androsace occidentalis, Salvia Pitcheri, Evol- 
vulus argenteus, Manfreda virginica, and Othake callosum. 
The region is particularly rich in species of Crataegus. 
Twenty-six species of ferns and fern allies are known 
to grow in the region under discussion, a number in 
which it will compare favorably with most areas of 
similar size in the Mississippi Valley. Most of the species 
have a wide range in the eastern United States, but a 
few are of less general distribution. Several which are 
common in the East are rare or local in this part of Mis- 
souri. Only one of the species listed, Filix fragilis, is 
found, except perhaps rarely, in the prairie region o 
Greene County, the others being restricted to the w ooded 
hills and valleys. 
In addition to Greene County, the writer has included 
the region about Graydon Springs, Polk County, only a 
few miles to the north, a locality of particular interest 
because of the large exposures of sandstone, resulting in 
the development of a peculiar flora similar in many 
