IOWA ACADEMY OF SCIENCES. 
207 
Cannabis. 
200. C. saliva L. Thickets, river banks and waste 
ground; common. 
URTICACE^. 
Urtica. 
-201. U. gracilis Ait. Damp ground; abundant. 
Urtioastrum. 
202. TJ. divaricatum (L.) Kuntze. {La])ortea canadensis 
^ Lindl.) Abundant in damp, shady ground. 
Adicea. 
203. A. jpumila (L.) Raf. (Pilea pumila Gray.) Shady 
places; abundant. 
B(EHMERIA. 
204. B. cylindrica (L.) Willd. Moist ground; frequent. 
Parietaria. 
205. Po pennsylvanica Muhl. Moist, shady places; 
abundant. 
SANTALACE^. 
COMANDRA. 
206. C. umhellata (L.) Nutt. Dry, open ground; com- 
mon . 
ARISTOLOHIACE^. 
As ARUM. 
207. A. canadenseJj. Common in moist woods. 
POLYGONACE^. 
Rumex . 
208. P. acetosella L. Dry, sterile ground; common. 
209. P. verticillatus L. Swamps and shallow ponds; 
frequent. 
210. P. altissimns Wood. Damp, open ground; common. 
211. R. patientia h. Moist ground; rare. 
212. P. hritannica L. Common in swamps. 
213. P. Crispins L. Waste places, especially in moist 
ground; abundant. 
