790 WEED FLORA OF IOWA 



BLOOMING PERIOD OF COMMON WEEDS— CONCIiUDED. 



Setaria vertioillata A. Wliorled foxtail 



Betaria viridis A. Green iCbxtail. 



Silene noctiflora A. Night-flowering- catcMy 



Solanum nigrum A. Night-shade. 



Sonchus arvensis P. Field thistle 



Saponaria officinalis P. Bouncing Bet 



Stipa spartea P. Needle grass. 



Strophostyles helvola A. Wild pea. , 



Syfnphoricarpos orbiculata P. Indian currant 



Tcmacetum vulgare P. Tansy , 



Lactuca scariola A. Prickly lettuce. ..'. 



Hibiscus trion/um A. Shoo-fly. 



Vr(ica dioica, P. Stinging nettle. , . . , 



Yernonia fasciculata P. Iron-weed. , 



Alutiloh theophrasti A. Velvet leaf. , 



Amaranthus retroflexus A. Tumbling pigweed. .. ., 



Aristida dicKotoma A. Poverty grass 



Artemisia Menhis B. Wormwood 



Artemisia ludoviciana P. Western mugwbrt , 



Aster multifloris A. Many-flowered aster , 



Aster sailicifoHus A. Willow-leaved aster , 



Bidens aristosa A. or B. Sticktight 



Oenchrus triiuloides A. Sandhur , 



Cfienopodium amirosioides A. Mexican tea 



Cirsium <aTtissimum B. Tall thistle. 



Cirsium [canescens B. Woolly thistle 



Cyperus esculentus P. Northern nut grass 



Dalea alopecuroides A. Foxtail dalea 



Digitaria sanguinalis A. Crab grass 



Echinochloa crusgalU A. Barnyard grass. 



Belianihus grosseserratus P. Wild prairie sunflower. 

 HeUantJius maximiliani P. Maxmilian's sunflower. . 



Selenium antumnale P. Sneezeweed , 



MuKlenbergia m,exicana P. Mexican dropseed 



Muhlenbergia racemosa P. Dropseed grass 



SoUdago canadensis P. Canada goldenrod 



Solidago rigida P. Stiff goldenrod 



Solidago serotina P. Goldenrod 



Panicum capillare A. Hair grass '.'...! 



Sporolol-us neglectus A. Small rush grass 



Sporohulus vaginiflorus A. Sheathed rush grass. . . , 



Xanthium canadense A. Cocklebur 



Xanthium spinosum A. Spined cocklebur 



Helianthus tuberosus P. Artichoke 



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