PLANTS OF IOWA 147 



1880. C. sychnocephala, Carey. Dense Long-beaked Sedge. 

 In marshes; infrequent. 



ARACE^. ARUM FAMILY. 



Aris^ema, Mart. 



1881. A. triphyllum. Indian Turnip. 

 Rich, moist woods. Frequent. 



1882. A. dracontium, (L.) Schott. Dragon-root. 

 In low moist ground; frequent. 



Spathyema, Raf. 



1883. 8. fwtida, L. Skunk Cabbage. 

 Swampy ground. Infrequent. 



Acorus, L. 



1884. A. calamus, L. Calamus-root. 

 Swampy ground; infrequent. 



LEMNACE.E. DUCKWEED FAMILY. 



Spirodela, Schleid. 



1885. 8. polyrhiza, (L.) Schleid. Great Duckweed. 

 Ponds. Common. 



Lemna, L. 



1886. L. trisulca, L. Ivy Leaved Duckweed. 

 Common. 



1887. L. minor, L. Lesser Duckweed. 

 Frequent, in ponds. 



Wolffia, Horkel. 



1888. W. columbiana, Karst, Columbia Wolffia. 

 Frequent. 



1889. W. punctata, Griseb. Punctate Wolffia. 

 Common in ponds. 



COMMELINAOffi. SPIDERWORT FAMILY. 



COMMELINA, L. 



1889a. C. crispa, Wooton. 



Rare, found in garden. 



