This is another serious invasive, usually found in wooded areas, having a significant impact on the ability of tree seedlings to establish and grow, as well as crowding out native understorey plants. These seedlings are growing in an area which I cleared entirely of large plants a week ago. I saw that there were hundreds of seedlings in that area, and today I checked on their growth. And yes, they are growing! In another week or two they'll be big enough for pulling without leaving the root in the ground.