TREES OF THE MISSOURI BASIN 
37 
growth of trees in the flood plain of this stream and on the hills 
adjacent to the stream. 
There is plenty of drift material in the valley of the Little 
Sioux between Sioux Eapids and Linn Glrove. 
Percentage of Trees, Little Sioux, Sioux Rapids, Buena Vista 
County. 
Name of Species 
Percentage. 
Plot No. 1, 
N. slope 
Percentage. 
Plot No. II, 
S. slope 
Percentage. 
Plot No. Ill, 
E. slope 
Percentage. 
Plot No. IV, 
W. slope 
Percentage. 
Bottoms, 
Plot No. V 
Quercus macrocarpa . . 
33.3 
20 
23.5 
25 
1 
Quercus rubra. 
7 
4 
7.5 
0 
0 
Tilia americana 
10 
6 
6 
12 
0 
Acer Negundo 
5 
1 
0 
0 
11 
Acer nigrum 
0 
9 
15 
0 
0 
Acer saccharinum .... 
0 
0 
0 
0 
10 
Prunus americana .... 
0 
0 
15 
5 
Prunus virginiana 
2 
0 
0 
0 
Crataegus mollis 
7.6 
0 
0 
5 
4 
tJlmus fulva 
14.1 
10 
5 
5 
4 • 
Ulmus americana 
5 
15 
8 
12 
5 
Ulmus Thomasii 
1 
0 
0 
10 
0 
Juglans nigra 
5 
0 
10 
0 
12 
Salix nigra 
0 
0 
0 
. 0 
12 
Salix amygdaloides ... 
0 
0 
0 
0 
11 
Gymnocladus dioica . . . 
Fraxinus pennsylvan- 
0 
0 
0 
0 
5 
ica var. lanceolata . . . 
4 
10 
0 
10 
15 
Populus deltoides 
0 
0 
0 
0 
5 
Ostrya virginiana 
3 
20 
20 
16 
0 
Garya cordiformis 
2 
5 
0 
10 
0 
Pyrus lowensis 
1 
0 
0 
0 
0 
A study of the distribution of the trees shows that the bur 
oak (Quercus macrocarpa) is a dominant tree in the drier 
situations and in many cases is distributed with the hard maple 
{Acer nigrum), basswood {Tilia americana), elm {TJlmus ameri- 
cana) and slippery elm {TJlmus fulva). The hard maple oc- 
curred in sheltered situations on the south and east slope. The 
corky bark elm was locally found near the Chicago & North 
Western railway on a slope of a hill adjacent to the Little Sioux 
river. It occurs here in considerable quantity. The Ostrya vir- 
giniana was commonly associated with the hard maple, basswood, 
slippery elm and red oak. 
