BIG SPRING PRAIRIE. 59 
bog formations. It is a Hydro-mesophytic Society, and 
can best be designated as a Potentilla fruticosa, Betula 
pumila, Salix myrtilloides, Rhus vernix heath. The 
last three species are the characteristic and common 
plants of Sphagnum swamps, either the simple Sphag- 
num swamp such as occurs at Fox Lake, Wayne Co., 
Ohio, or the Tamarack Bog as the one on the Calumet 
flood plain at Millers, Ind. 
It is still an unsolved problem whether these spec- 
ies are remnants of a former Sphagnum swamp, or 
whether they are ever associated together on areas 
where Sphagnum moss has never occurred. 
Big Spring Prairie marks the southern limit for 
the range of Retula pumila in Ohio. Besides the Salix 
myrtilloides, there also occurs Salix candida, Salix beb- 
biana, and Salix lucida. The Salix candida is the next 
most common species to Salix myrtilloides. Close to 
the shallow old ditch along the western margin there 
occur occasional large willows and poplars. In some 
portions the Potentilla fruticosa predominates as in 
field just south of the divide, while at others there are 
various combinations of the remaining characteristic 
species. The remaining shrubby plants are Rosa caro- 
lina, Cornus stolonifera, and Ribes floridus, the last the 
least abundant. 
The principle grasses and sedges are Chrysopogon 
avenaceus (Michx.) Benth. (Indian Grass); Phragmites, 
(Reed); and Carex (various species). 
The principle herbaceous plants are Solidago rid- 
dellii (Riddells Goldenrod); Solidago ohioensis (Ohio 
goldenrod); Allium cernuum (Nodding Onion); Lacin- 
aria spicata (Gay feather Devils-bit) and Dryopteris 
thelypteris (Marsh Shield Fern.) In fig. 11, the Solid- 
agos are shown to the left of the ditch chiefly. 
The Allium and Lacinaria in field in vicinity of 
Ox Spring were found to be by far the most abundant 
on the marly streaks and areas; they occur much less 
