94 JOURNAL OF THE MITCHELL SOCIETY [ June 
Little is known concerning a rare bracken, Pycnadoria longifolia, 
within our range, and it may yet prove to be a native plant. There 
seems to be no good reason why it should not be native, for it occurs 
plentifully on the islands on the other side of the Gulf Stream. The 
other exotic has found such favorable habitats and grows in such a 
natural manner that it is difficult to realize that it is not a native 
plant. In fact, never has a satisfactory explanation been offered as 
to how the large wood-fern, Dryopteris setigera, did gain a foothold 
in these apparently natural habitats. Of course, it may be that its 
spores were primarily carried there by winds from cultivated plants 
and thus lodged in favorable habitats. But the true manner of its 
introduction may remain a mystery forever. The pepperwort, 
Marsilea vestita, is native west of the Mississippi River. It seems to 
have been brought into Florida through the agency of the railroads, 
and as far as we know it has not been found far away from the lines of 
traffic. 
Two additional species, a bracken, Pycnadoria cretica, and a 
clubmoss, Lycopodium cernuwm, are sometimes considered naturalized 
plants, but there has never been good evidence advanced to support 
that theory. 
There are seven endemic ees in Florida. These are: 
Asplenium rebar nenes (Spleenwort) 
Asplenium Curtiss 
Tectara pa st (Halberd-fern) 
Selaginella serene (Resurrection-plant ) 
Selaginella humifus 
Isoetes Chapmanii ( (Quiltwort) 
Isoetes alata 
The first-mentioned spleenwort grows in only one hammock—a 
hammock on the Everglade Keys, in the southern end of the Ever- 
glades, while the second one is found in hammocks in the lime-sivk 
region of the northern part of the peninsula. The Tectaria is known 
only in the hammocks of thé Everglade Keys. The first-cited species 
of Selaginella oceurs in peninsular Florida, while the second one has 
been found in northern Florida, as well as in the peninsula. The 
first-mentioned quillwort has been found only in western Florida, 
while the second one is known to oceur only in the Gulf Hammock 
region. This region is a rather narrow strip along the upper western 
coast of the peninsula with limestone near the surface or cropping out. 
The coast line differs from that farther south in being devoid 0° 
