Callitriche stagnalis Scop.
pond water starwort, common European water starwort
pond water starwort, common European water starwort
April 27,
Blue Hill R., Blue Hills Reservation, Randolph
Many upper-stem leaves are 5 mm wide and wider. 5 veins are distinguishable in each floating leaf of the alien species (while in the native species, variable water starwort, there are only three conspicuous veins in each floating rosette leaf).