The discovery of Morison's spurry in Massachusetts belongs to Tom Palmer of Milton. As of 2015, his sample remained the only
one in the thin folder representing this plant in the Harvard University Herbaria. Morison's spurry is not difficult to identify,
once you find its seeds. Each seed has a relatively wide wing (about 0.3 mm on average, sometimes even 0.5 mm), while a seed
of S. arvensis, which has been traditionally the only species recognized as common in Massachusetts, has a wing less than 0.1 mm wide. Besides,
that seed is nearly globose, not as flat as the seeds in this photo.