Resupinate Bladderwort, Utricularia resupinata, Threatened, and Subulate Bladderwort, Utricularia subulata, Special Concern. The MESA list is updated approximately every 3 to 4 years, and it is as accurate as the biologists can make it.
All species listed as Federal Endangered or Threatened are by statute automatically protected under the Massachusetts MESA. Massachusetts has 4 federally listed plant species:

Small Whorled Pogonia, Isotria medeoloides, (State listed as Endangered, Federally listed as Threatened);
Northeastern Bulrush, Scirpus ancistrochaetus (State listed as Endangered, Federally listed as Endangered);
Sandplain Gerardia, Agalinis acuta (State listed as Endangered, Federally listed as Endangered); and
Chaff-seed, Schwalbea americana (State listed as Endangered, Federally listed as Endangered).