The state of Montana has put a new weed at the top of its noxious weed priority list.

"We did have a Common reed, which is also called Frank Mighty's," Weed Program Manager Dave Burch said.  "We added that to our priority 1A list. There's a lot of Common reed but native Common reed in the state, but there are some invasives coming in as well and we found one patch of invasives in the Hill County area."

Non-native common reed can grow up to 16 feet tall and spreads along riparian areas, blocking the sunlight from other native plants. Authorities have put it at the highest level of risk, a class that has only two other noxious weeds.

"We have them listed as Yellowstar thistle which, knock on wood, we don't have any in the state or we haven't had any sightings for the last three years," Burch said. "Dyer's load, which is a real bad plant, especially in Utah and Idaho now, and then Common read. States like Nebraska and Wyoming have huge problems with it. It completely crowds out everything."

The state of Montana also added some aquarium plants to its priority 3 list, which means the will be regulated and prevented from sale. Burch said the aquarium plants pose a risk if they are dumped in Montana waterways.