Jef Taylor reports [2] finding some beach rose along the Green Line on Comm. Ave. by BU. And them's good eatin':
They were quite tasty, I suspect they had been through a frost, which is known to improve their flavor.
Links:
[1] http://www.universalhub.com/users/adamg
[2] http://urbpan.livejournal.com/1413885.html
[3] http://www.universalhub.com/allston
[4] http://www.universalhub.com/dining