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IOWA ACADEMY OF SCIENCE Vol. XXIV, 1917 
over the hill top and down the south side, was selected for de- 
tailed observation as to soil, atmosphere, and other conditions 
affecting plant growth. 
Typical stations were selected as follows : 
Station I on the river flat, 8 feet above the river, in ordinary 
season, and 24 feet south of it. 
Station II near the foot of the bluff, 44 feet above the river, 
and 400 feet south of it. 
Station III in the timber, half way up the bluff side, 820 feet 
south of, and 119 feet above, the river. 
Station IV, 1,230 feet south of the river, 164 feet above it, 
located on the open prairie. 
The total area in forest on this tract studied was about 160,000 
square feet. The area in pra’rie was about 100,000 square feet. 
It will be seen by the plant lists of the several stations that 
the flora of this locality does not comprise a large number oi 
species of flowering plants. The number of flowering plants 
native to the upper Mississippi yalley is considerably more than 
a thousand, and our list here is limited to 162 species. The lo- 
cality is so far west and north that, for Iowa, it has severe 
conditions. The plants of the prairie are largely plants of the 
western plains, while the flora of the forests has more the appear- 
ance of the forests farther east. In accordance with the prairie 
conditions we find that 62 per cent of the dry prairie plants 
of station IV are of a type unsuited for the more protected 
tracts of stations I, II, or III, and do not occur at these stations 
at all. Typical of these plants are Andropogan scoparms and 
Andropogan fur cat us, Anemone patens var. Wolfgangiang, Aster 
sericeus and Aster oblongifolius, Bouteloua curtipendula and 
Bouteloua hirsuia, Grindellia squarrqsa, Helianthus scab err imus, 
Kuhnia eupatorioides var. corymbulosa, Petalostemum candidum 
and Petalostemum purpureum,- Soli dago missouriensis and 
Solidago nem oralis, and Vida pedatifida. These plants are 
characterized by devices for protection from the drying effects 
of the hot southwest summer winds, and the scorching effects 
of the blazing summer sun. In some the leaves are markedly 
firm and rigid ( Solidago missouriensis and Helianthus seaber- 
rimus), or are clothed with hairy coverings ( Solidago nemoralis, 
Kuhnia eupatorioides var. corymbulosa, Aster sericeus and 
Anemone patens var. Wolf gam gi ana). In others the leaves are 
