A recent report published by the Institute of Science in Society discusses glyphosate resistance in weeds. From the report:
In regions of the USA where transgenic glyphosate resistant crops dominate, there are now evolved glyphosate-resistant populations of the economically damaging weed species Ambrosia artemissifolia (rag weed), Ambrosia trifida L.(great ragweed), palmer pigweed (Amaranthus palmeri), common water hemp (Amaranthus rudis) , rough fruit amaranth (Amaranthus tuberculatus) and various Conyza (horse weed ) and Lolium (rye grass) species.
Likewise, in areas of transgenic glyphosate resistant crops in Argentina and Brazil, there are now evolved glyphosate resistant populations of Johnson grass (Sorghum halepense) and Mexican fireplant (Euphorbia heterophylla). These herbicide resistant weeds pose a clear threat to the transgenic crops dominating North and South America .
Read the entire report here.