350 BOTANICAL GAZETTE [DECEMBER 
of the cliff (but away from the exposed sandy terrain), in a second 
growth Quercus rubra-Q. alba association, with considerable under- 
growth of Cornus, Viburnum, and seedlings of Prunus, etc. Sta- 
tions 5, 3, and 2 were located on talus slopes, no. 5 about one-third 
of the way down one, on the face of the cliff, and nos. 3 and 2 near 
the tops of slopes on opposite sides of Hennepin Canyon. The 
tree growth at station 5 was predominantly Quercus rubra, with 
some Q. alba, Juglans cinerea, and Tilia americana, and a scattering 
of other mesophytic hardwood species. The shrubby undergrowth 
consisted mostly of Hamamelis virginiana, and the herbaceous situa- 
tion was dominated by a magnificent ‘“‘fernery”’ of Osmunda clay- 
toniana. ‘The soil here was a sand rich in humus, but with little 
clay. Station 3, within the canyon, was on a rather newer slope, 
the soil containing a considerable proportion of clay. The tree 
growth consisted largely of Prunus serotina, and there was a dense 
undergrowth of Psedera quinquefolia, Ribes cynosbati, Lonicera 
Sullivantit, and Hydrangea arborescens. There was also a fair 
development of mesophytic herbs. Station 2 was on a slope that 
was newer still. The soil was sandier than on station 3, but raw 
and poor in humus. It was full of stones, with large, moss-covered 
rocks protruding. There were fewer trees, and these were mostly 
young and small. A very considerable growth of Hamamelis 
virginiana was present, but few other shrubs, and almost no herbs. 
These three stations represented fairly well the state of the more 
mesophytic talus slopes. Stations 4 and 1 were on representative 
bottomlands, no. 4 being on the river floodplain and no. 1 on the 
floor of the canyon. The soil in both places was a black alluvium. 
The association at station 4 was dominated by Acer saccharinum 
and Ulmus americana, with many seedlings and saplings. Other 
undergrowth was mostly herbaceous, with Laportea canadensis, 
Boehmeria cylindrica, and Campanula americana as the conspicuous 
species. The alluvial floor of the canyon, where station 1 was 
located, bore an association of Ulmus, with some admixture of 
Juglans, Fraxinus, Populus, Salix, etc. Seedlings and young 
trees were numerous, and there was a fair amount of undergrowth, 
consisting largely of Sambucus canadensis, and at one place a notable 
icket of Euonymus. There was an exceedingly rich, moist- 
