IOWA ACADEMY OF SCIENCES. 
275 
R. crispus L. Curled Dock. Wayside. Common. 
Polygonum aviculare L. Knot weed. Common in yards 
P. pennsylvanicum L. Common in wet places. 
P. persicarioides. H. B. K. Waste places; quite common. 
P. hydropiperoides L. Michx. Mild Water pepper. Wet 
soil; frequent. 
P. hydropiper L. Common Smart weed or Water pepper. 
Wet land. Common. 
P. virginanum L. Woods; frequent. 
P. convolvulus L. Black Bindweed. Fields. Common. 
P. dumetorum L. var. scandens Gray. Climbing False 
Buckwheat. Moist thickets. Common. 
Fagopyrum esculentum Moench. Buckwheat. Escaped 
from fields. 
Aristolochiace^e. Birthwort Family. 
Asarum canadense L. Wild Ginger. Hillsides in rich, 
woods. Common. 
Thymelaeace^e. Mezereum Family. 
Direct palustris L. Leatherwood. Moosewood. Woods;: 
rare. 
Euphorbiace^e. Spurge Family. 
Euphorbia glyptosperma Engel m. Roadsides; infrequent. 
E. heterophylla L. Dry soil; not common. 
E. cyparissias L. Cemeteries; escaped from cultivation. 
E. corollata L. Open woods. Common. 
Urticace^e. Kettle Family. 
Ulrnus fulva Michx. Slippery or Red Elm. Rich upland 
and bottoms; common. 
U. americana L. American or White Elm. Common on 
river bottoms. 
U. racemosa Thomas. Cork or Rock Elm. Not common. 
Celtis occidental is L. Hackberry. Sugarberry. Quite 
common on bottom land. 
Cannabis sativa L. Hemp. Roadsides; escaped from 
cultivation. 
Hamulus lupulus L. Common Hop. Thickets; common. 
