It's shepherd's purse. You can
buy on line, e.g.
http://www.amazon.com/exec/obidos/tg/detail/-/B0002QVTHA/qid=1125264037/sr=8-3/ref=sr_8_xs_ap_i3_xgl86/102-2732743-0339328?v=glance&s=garden&n=507846
I had no experience dealing with them, since chinese mkts here sell them in frozen packages cheaply.
http://www.amazon.com/exec/obidos/tg/detail/-/B0002QVTHA/qid=1125264037/sr=8-3/ref=sr_8_xs_ap_i3_xgl86/102-2732743-0339328?v=glance&s=garden&n=507846
I had no experience dealing with them, since chinese mkts here sell them in frozen packages cheaply.