]> NEBC barcode-00875188 United States of America Massachusetts Concord, near culvert tunnelling B & M RR [Boston & Maine Railroad] embankment, so. of Walden P. [Pond] Spirodela polyrrhiza (Linnaeus) Schleiden (Linnaeus) Schleiden 2020-04-22 09:06:40 R. J. Eaton & C. Schweinfurth