3 6 IOWA ACADEMY OF SCIENCE 
■» 
Percentagf: of Distribution of Trees, Missouri Valley, Harrison 
. County. 
Name of Species 
Plot I. Areas 1-6. 1 
Plat, second bot- I 
tom, sandy 
Plot II. Areas 7-10. 
overflow bank, 
Missouri river, 
sandy 
Plot III. Rolling 
timber, areas 1-3, ' 
northeast slope 
Plot IV. Areas 4-7, 
S. and E. slope 
PlofV. Areas 
8-10, N. slope 
Plot VI. N. 
.slope 
Plot VII. Yellow 
loess, NW. slope 
Ulmus americana 
15.10 
34.8 
6.76 
18.78 
6 
1.23 
Ulmus fulva 
3.02 
1.09 
8.45 
26.96 
6 
1.23 
Juglans nigra 
1.51 
15.26 
41.59 
44.76 
2 
Praxinus pennsylvanica. . 
12.08 
7.63 
3.38 
Acer Negundo 
3.02 
”216 
A.cer saccharinum 
3.02 
Cornus asperifolia 
22.65 
Gleditsia triacanthos 
3.02 
44 ”' 
3l'98 
Carya ovata 
3.02 
To9 
Carya cordiformis 
2.89 
~4'76 
2 "" 
Crataegus mollis 
4.53 
1014 
10 
2.46 
Ostrya virginiana 
24,16 
30"5' 
10.14 
Celtis occidentalis 
1.51 
1.19 
15.13 
iTso 
Gymnocladus dioica .... 
1.51 
Populus deltoides 
0 
18.6 
~8~6i 
Salix amygdaloides 
0 
29 
Salix missouriensis 
0 
20 
Salix fluviatilis 
0 
32.24 
"I 23 
Salix nigra 
0 
11.07 
Tilia americana 
0 
5 I 5 
18'46 
s'” 
Quercus macrocarpa .... 
0 
iT69 
. 2.38 
20 
Quercus rubra 
0 
2.38 
2 
Eleagnus hortensis var. 
Songorica 
0 
2.46 
Prunus americana 
0 
— 
— - 
____ 
— - 
36.90 
DISTRIBUTION OP TREES IN NORTHERN BUENA VISTA COUNTY. 
The following data are based on a study of the forest flora 
of Buena Vista county by B. L. Bradford. The study con- 
cerned itself chiefly with the trees of the Little Sioux, which is 
in the northern part of the county and forms a part of the Mis- 
souri river basin. The geology of this region has been discussed 
by Maebride. 
A part of the "drainage of this county is towards the Des 
Moines and hence towards the Mississippi; the Kaccoon river 
belongs to the Des Moines drainage basin and the Little Sioux 
to the Missouri. The cutting of the Little Sioux by the enor- 
mous amount of water during the glacial times has made a 
well deflned valley and consequently has made possible the 
