3908 MINNESOTA BOTANICAL STUDIES. 
The plants which form large trees on the islands are: 
Acer saccharinum, Populus deltoides, 
Betula nigra, Quercus platanordes, 
Frraxinus lanceolata, Salix amygdaloides, 
Fraxinus nigra, Olmus americana. 
Gleditsia triacanthos, 
The following species do not attain large size, but are either 
scattered throughout as shrubs or small trees, or form a dense 
low growth on some of the lower grounds of the mud flat. 
(Plate XXY .; A.) 
Cephalanthus occidentalis, Salix fluviatilis, 
Cornus amonum, Salix nigra. 
Three species of woody vines are common throughout the 
islands. The Virginia creeper, Parthenocissus quinguefolia, 
and wild grape, Vzt¢s vulpina, are abundant, covering and in 
many cases killing large trees. The climbing poison ivy, /thus 
radicans, is common throughout the most densely wooded parts. 
It sometimes climbs to a height of twenty-five or thirty feet, and 
develops a stem from two to three inches in diameter. 
During the late summer and autumn the mud-flat throughout 
is covered with a dense growth of coarse herbs most of which 
are perennials. 
The following herbaceous plants grow on the mud-flat. 
Acnida tamariscina, Mimulus ringens, 
Apocynum cannabinum, Onoclea senstbilis, 
Arisema dracontiun, Polygonum hartwrighti, 
Bidens comosa, Polygonum hydropiperoides, 
Bidens frondosa, Polygonum incarnatum, 
Bidens levis, Polygonum punctatum, 
Cicuta bulbifera, Polygonum virginianum, 
flelenium autumnale, Physalis philadelphica, 
Ilysanthes gratioloides, Physostegia virginiana, 
Lippia lanceolata, Ranunculus pennsylvanicus, 
Lobelia cardinals, Scutellaria latertflora, 
Lycopus americanus, Stachys palustris, 
Lycopus lucidus, Stezronema ciliata, 
Lycopus rubellus, Teucrium canadense, 
Lycopus virginicus, Urtica gracilis, 
Lythrum alatum, Urticastrum divaricatum. 
Mentha canadensis, 
