172 
FIFTEENTH REPORT. 
140. Cory 1 us Americana, Walt. Hazelnut. 
Thickets. Common. 
There are two forms of this species; the common form from 
four to eight feet in height with the involucre open and spreading; 
and another, about 17 feet in height, with the involucral bracts 
erect or closed; the latter form was found on the edge of the 
upland woods with a sunny, southern exposure. I found the same 
thing at Algonac, but at this place it was in a dense, wet alder 
thicket. The leaves appear to be less leathery. 
Family 23. Betulaceae. 
147. Betula pumila, Lin. 
Tamarack swamps. Common. 
Familly 24. Castaneaceae. 
148. Fagus grandifolia, Ehrh., Yar. Caroliniana (Loud.) Fernald and 
Bheder. Beech. 
()])en woods. Frequent. 
149. Quercus alba, Lin. White Oak. 
Woods. Common. 
The bark of this, as well as of other species, is a commercial 
article and is used in medicine as an astringent in treatment of 
diarrhoea, etc. II is official as Quercus. 
150. Quercus ellipsoidalis, E. J. Hill. Black Oak. 
Upland woods. Bare. 
151. Quercus macrocarpa, 11 x. Bur Oak. 
Low grounds. Common. 
152. Quercus velutina, Lam. Black Oak. 
Woods. Frequent. 
Order XI1T. Urticales. 
Family 25. Flmaceae. 
153. 1 Tunis Americana. Elm. 
Low grounds. Common. 
Family 20. Urticaceae. 
154. Frtica dioica, Lin. Nettle. 
Waste places. Frequent. 
The leaves and roots are commercial articles and are used in 
medicine as diuretics in cystitis, nephritis, etc. 
155. Frtica. gracilis. Ait. Nettle. 
Low grounds. Frequent. 
150. Frticastrum divarication l L) O. K. Wood Nettle. 
Low grounds in open woods. Common. 
157. Boehmeria cylindrica (Lin.) Swz. False Nettle. 
Low grounds. Common. 
Order XI Y. Polygonales. 
Family 27. Persicariaceae. 
158. Ihiniex Acetosella, Lin. Sorrel, Sheep Sorrel. 
Sterile grounds. Common. 
Contains oxalic acid. It is a commercial article under the 
name of Sheep Sorrel and is used as a refrigerant and diuretic in 
treatment of inflammatory disease. 
159. Bumex Briiannica; Lin. Water Dock. 
Swamps. Bare. 
