They're called water chestnuts. They are a fast-growing aquatic plant that sits on the surface of the water, but grows a lengthy, tangled root 12 to 15 feet long.
At Lake Towhee Park in Haycock, the water chestnuts are starting to take over. That's something officials at nearby Lake Nockamixon want to avoid because when these plants invade, it only means trouble.
"People aren't going to be able to boat, people aren't going to be able to kayak, we're going to have problems with our fish, our geese, so we want to keep that from happening," Beth Clark, an environmental education specialist, said.
Water chestnut has been spotted growing in the southern end of Lake Nockamixon.
Bob Lengel of Milford Square, Pennsylvania, knows what it's like to have a boat caught up in something like that; it t happened to him in New York.
"It really was clogging up and I had to full blast to get out of there. Fortunately, we weren't too deep into the stuff," Lengel said.
To help eradicate water chestnuts, park officials are holding what they call "pulling parties," where volunteers manually remove the plants from the lake. Doing it by hand makes it easier to pluck out the bad stuff and save the good plants
"We can target the plants we want to get out as opposed to a chemical treatment or mechanical treatment," Clark said.
Park officials are warning boaters when they come out of the water to check for and dispose of the seed pods from the water chestnut plant. The spiky nuts are sharp enough to pierce a tire and can easily be transported from location to location.
