JANUARY, 1902. BRUNCKEN STUDIES IN PLANT DISTRIBUTION. 
19 
imis nigra are by far the most numerous, silver and red maple (3) 
are interspersed very sparingly, Ulmus fulva a little more fre- 
quently, and Quercns bicolor is common. The underbrush con- 
sists of many species of SalLr, Cormts, Viburnum, etc. Creepers, 
such as Ampelopsis, Lonicera, Smilax are characteristic of this 
as well as the second group of this sub-association, while they are 
practically unknown in the other forest associations (with the 
exception of Evonymiis) . The soil is probably sour in not a few 
cases, as w^ould be indicated by the rich development of swamp- 
loving mosses, Cyperaceae, etc. Phanerogamic herbs growing 
under the shade of the trees mostly have some xerophytic charac- 
ters (Viola blanda and Labradorica, Majanthemum Canadense, 
etc.), in sharp contrast to the hydrophytic flora towards the 
middle of the swamps. 
The second group of the hemi-hydrophytic sub-association, the 
iDottom woods, has been more disastrously affected by human ac- 
tivity than any other portion of the forests of the region, except 
the tamarack association. There can be little doitbt that previous 
to the settlement of the country this group occupied the entire val- 
leys of the Milwaukee, Menomonee and Kinnickinnic Rivers with 
the exception of the sedge and wild rice marshes at their mouth, 
and perhaps isolated patches of tamarack swamp and hydrophytic 
shrubbery. To-day a few small remnants is all that is left of the 
bottom forest, such as the grove near the junction of Honey Creek 
and the Menomonee. On the pastures which now form the largest 
part of the river valleys, there are scattered a good many groups 
and individual trees, some of them in full vigor, others in various 
stages of decay, stag-headed and hollow-boled. From these rem- 
nants, however, it is possible to draw a mental picture of what 
these woods must have looked like when they were in their pris- 
tine glory. Three species of elm {Ulmus Americana, fulva and 
racemosa) seem to have furnished the most numerous host; as- 
sociated with them were Celtis occidentalis, which now remains 
only in comparatively few individuals, the largest group known to 
the writer growing near the County Insane Asylum, Quercns bi- 
color, Acer dasycarpum, Acer Negundo, Populus deltoides, Frax- 
inus nigra, Salix amygdaloides. The trees in this group seem to 
have grown to very great dimensions, if one may judge from the 
giants which still remain. Creepers of the species mentioned above 
were abundant. It is probable that the forest was interrupted by 
considerable areas covered with shrubs. Such thickets have again 
come up in many places since the original growth was destroyed. 
(3) Young red maple trees are occasionally found among young growths of 
liard maple, away from the proximity of swamps. 
