Does anyone know whether any of the ethnic or Asian supermarkets in the area sell this extremely delicious veggie? Have not been able to find it at any of my local H-marts and GrandMarts (Gaithersburg area). I would love to get some and cultivate them in a pot on my balcony. Apparently they are considered invasive weeds, so it's illegal to import seeds acrosss state lines, but fine if receiving the grown veggie. Any help?