PLANT STUDIES IN LYON COUNTY 
401 
Station III. Elymus st rictus is an example of a plant more at 
home in the woods of Station III, as shown by the number of 
specimens, but able to extend its range upward to the dry prai- 
ries, where a few appear. Anemone cyUndrica is an illustration 
of a plant at home on the dry prairie, but able to accommodate 
itself to the drier parts of the woods, so that a few specimens 
appear at Station III. Of the plants at Station III, which appear 
abundantly at Station II, Quercus macrocarpa, TJlmus fulvci, 
S'ilene st elicit a, Ostrya virginiana, Frag aria vesca var. americana, 
and Aquilegia canadensis illustrate those which must have some 
protection, and flourish best where the shelter is good. Quercus 
macrocarpa illustrates well the effect on the hardiest trees of the 
difference in the conditions for growth due to variation in shel- 
ter. The 190 specimens found on the tract studied are all grouped 
in Stations II and II T, with the taller, thicker trees almost in- 
variably lower down, and those near the upper tree limit low, 
small in diameter, and gnarled and stunted in every way (see 
Plate. XI, I and II) . Station III marks the upper tree limit for a 
number of the hardier trees as well as the limit for a number of 
the hardier herbaceous plants which extend up through all the 
stations until they come to the extreme conditions of the dry 
prairie. Examples of these are Acer N eg undo, which shows regu- 
lar diminution in size from Station I to Station II, Ribes gracile, 
also much more vigorous and numerous at Station I than at 
Station II and Station III, Fraxinus pennsylvanica var. lanceo- 
lata, Tilia americana, and Arctium, minus, all showing the same 
traits as to size and vigor. Of plants found only in the upper 
woods typical examples are Monarda fistulosa, Primus virginiana, 
Rosa blanda, Liatris scariosa, Lepacliys pinnata, Heliopsis scabra, 
and Cary a glabra. Strays able to hold their own are illustrated 
at this station by Celastrus scandens, Juniperus virginiana, Lac- 
tuca scariola , and Trifolium pratense. 
The extent of variation in conditions at the several stations 
is indicated by the variation in flora, 20 per cent of the entire 
number of species being found at Station I, and nowhere else, 3 
per cent of the entire flora appearing only at Station II, 17 per 
cent of it growing only at Station III, and 21 per cent of it 
only at Station IV. Only 1.8 per cent of the entire flora is able 
to adapt itself to the conditions found at all of the stations, 8 
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