788 WEED FLORA OF IOWA 



BLOOMING PERIOD OF COMMON WEEDS— C!ontinued. 



Acalypha virginica A. Three-seeded mercury 



Amaranthus graecizans A. Tumbleweed 



Amaranthus blitoides A. Spreading pigweed... 



Anthemis cotulla A- Mayweed 



Apocynum oannaMnum P. Dogbane 



Asclepias synaca P. Milkweed 



Berteroa incana A. or P. Berteroa 



Brassiea nigra A. Blacli mustard 



BrOTTiMS secaliniis A. Cheat 



GanteUna sativa A. False flax 



Garex vulpinoi&ea P. Sedge 



Ghenapodium alium A. Lamib's quarter 



CictUa maculata P. Cowbane 



Girsium arvense P. Canada thistle 



Girsium undulatum B. Wavy-leaved thistle 



Grotalaria sagittalis A. Rattle-box 



Gycloloma atriplicifolium A. Winged pigweed 



Datura stramonium A. Jimson weed 



Daucus carota B. Wild carrot 



Erigeron annuus A. Fleabane 



Erigeron canadensis A. Horseweed 



Erigeron ramosus A. Branched fleabane 



Euphorhia maculata Spotted-leaved spurge 



Geum canadense P. Avens 



Helianthus petiolaris A. Petiolate sunflower... 



Hordeum ju'batum A. or B. Squirrel-tail 



Hypericum perforatum P. St. John's- wort 



LactUiCa canadensis A. or B. Wild lettuce 



Lactuca pulchella P. Blue lettuce 



Lappula virginiairw, A. Beggar's lice 



Leonurus cardiaca P. Mother-wort 



Lygodesmia juncea P. Lygodesmia 



Melanthium virginicum P. Bunch flower 



Melilotus alha B. White sweet clover 



Oenothera 'biennis B. Evening primrose 



Parietaria pennsylvanica A. Pellitory 



Fastinaca sativa P. Parsnip 



Plantago rugelii P. Rugel's plantain 



Polanisia trachysperma A. Polanisia 



Polygonum avioulare A. Dooryard knotgrass 



Por.ygonum hydropiperoides P. Mild water pepper 

 Polygonum lapathifoUum A. Slender smartweed . . 



Eleusine indica A. Goose-grass 



Eragrostis megastachya A. Candy-grass 



Linaria vulgaris P. Toadflax 



Silene antirrhina A. Sleepy catchfly 



Thlaspi arvense A. Pennycress 



Urtica gracilis P. Nettle 



Gonringia orientalis A. Hare's-ear mustard 



Polygonum persicaria A. Lady's thumb. 



Portulaca oleracea A. Purslane 



Radicula armoracia P. Horseradish 



Raphanus sativvs A. or B. Radish 



Rumex crispus P. Curled dock 



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