Yes, I think it's a wild plant. It grows naturally in this area. It
reseeds readily as well as being a perennial, so I don't think the milk
carton would prevent it getting into places where it's not welcome.
The roots are rather tuberous and a small plant can have a rather large
one quickly. Even leaving a piece of the root is enough to form a new
plant. Still, too many of the aggressive weeds here aren't nearly as
attractive as this one.
Texas Zone 7b, USA
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