Most definitely! You said "barn." I've often seen many introduced herbs such as motherwort, nettle, burdock, and more on old farmsteads - my own place included. While some find motherwort weedy, it does have appeal like being a medicinal herb and its lavender flowers are a great bumblebee magnet. FataMorgana

man this one is very stubborn. The root is like dandelion's but not that deep, If I hand pull them the root won't come up. I have the dandelion digger but there's lots and lots of these in my lawn. I notice that me and my other two neighbors also have this kind of weed, but not everyone in the neighborhood. This weed is not very common in my area... so any idea why that is? I hand pull them 2 weeks ago and now look at how fast they've grown back!!

i dont think touching is an issue.. it would be more an issue of getting falling down drunk.. falling with your mouth open.. into the pot.. and swallowing it .. lol ... like the shroom would be the worst of your problem at that point.. lol ... i didnt realize its in a pot.. if so.. just put on a glove if you wish [i wouldn't bother].. and tug it out .. it doesnt really have roots ... no need to keep it.. if you dont want ... in pots.. you would be better off with one of the potting media ... and when i used to grow seed.. i sterilize my media... before use.. to not only get rid of weed seed.. but also fungi spores..etc ... see link... ken Here is a link that might be useful: link

Since you don't want it, shovel up the roots to get rid of whatever it is. If there are orange/purple potatoes, it's sweet potato. I doubt that's what it is since they are still dormant here. If it's Houttuynia, you can't garden that spot until you get rid of this. Little pieces of root not found/removed can keep growing new plants. Smothering might work for you. Can you add a pic of the whole area?