This is a weed of warmer American regions. JC was lucky to be present in 2005 for the coll. from Ky. in MCRE (KNK), perhaps the last new state-record of our beloved, lately deceased John Thieret. At the first stop on a grand tour, JT spotted it at the edge of the parking lot behind the Stearns restaurant. It persisted here for at least 5 years.