PLANTS OF IOWA 195 



.2524. V. lanceolata, L. Lance-leaved Violet. 

 In wet places. 



2525. V. pubescens, Ait. Hairy Yellow Violet. 

 Common in woods. 



2526. V. scabriuscula, (T. & G.) Schwein. Common Yellow 



Violet. 

 Common in rich alluvial woods. 



2527. V. canadensis, L. Canada Violet. 



Common in rich woods, especially on lower banks and 

 slopes. 



2528. V. tricolor, L. Pansy. 



Escaped from cultivation; infrequent. 



CACTACE.E. CACTUS FAMILY. 



OPUNTIA, Mill. 



2529. 0. humifusa, Raf. Western Prickly Pear. 

 Infrequent, western part of state. 



THYMELEACE^. MEZEEEON FAMILY. 

 DlRCA, L. 



2530. D. palustris, L. Leather-wood. 

 Not common. 



OLEASTER FAMILY. 



LEPARGYRJEA, Raf. 



2531. L. argent ea, (Nutt.) Greene. Buffalo-berry. 

 Not common. 



LYTHRACE^;. LOOSESTEIFE FAMILY. 



AMMANNIA, L. 



2532. A. coccinea, Rottb. Long-leaved Ammannia. 

 Frequent. 



DIDIPLUS, Raf. 



2533. D. diandra, (Nutt.) Wood. Water Purslane. 

 Infrequent. 



HOTALA, L. 



2534. R. ramosior, (L.) Koehne. Rotala. 



In wet soil, common. 



