« Humans have been at war with weeds since humankind ceased living as hunter-gatherers and became agriculturalists thousands of years ago. »

Sanford S. Singer, « First Modern Herbicide Is Introduced », in Rasmussen R. Kent, « Agriculture in History« , éd. Salem press, 2010 p.757

Smooth pig weed Amaranthus hybridus A-B
Spiny amaranth Amaranthus spinosus A-B
Wild oat Avena fatua A-G
Common lambsquarters Chenophodium album A-B
Field bind weed Convolvulus arvensis P-B
Bermuda grass Cynodon dactylon P-G
Yellow nut sedge Cyperus esculentus P-S
Purple nut sedge Cyperus rotundus P-S
Crab grass Digitaria sanguinalis A-G
Jungle rice Echinochloa colonum A-G
Barnyard grass Echinochloa crusgalli A-G
Water hyacinth Eichhornia crassipes P-B
Goose grass Eleusine indica A-G
Cogon grass Imperata cylindrical P-G
Sour paspalum Paspalum conjugatum P-G
Common purslane Portulaca oleracea A-B
Itch grass Rottboellia exaltata A-G
Johnson grass Sorghum halepense P-G

G-grasses; S-sedges; B-Broad leaf weeds.