MINNEAPOLIS (AP) - Some seed mixes used to grow more habitat for bees and wildlife have been contaminated with an aggressive and prolific weed that can be a scourge for farmers, including those in Minnesota.

Reports of Palmer amaranth was discovered in Minnesota for the first time after weed seeds were accidentally planted on conservation land. Palmer is one of the most harmful weeds in the country for corn, soybeans and other row crops.

A Yellow Medicine County farmer reported Palmer in his newly planted conservation land in September. Since then, Minnesota agriculture officials have confirmed the weed in 30 plantings by 13 landowners in Yellow Medicine and Lyon counties.

All were planted with contaminated seed traced to the same company, which officials haven't identified because the investigation is ongoing.