During a Travel Team survey expedition to Big Lake, Washington county, Maine, during June 2025, Dale found a puzzling plant whilst snorkeling for Variable leaf milfoil. The identity of the plant in its immature stage eluded all who were surveying on this trip.
About a day later he found a complete plant that had both these basal leaves as well as a long thin stem on which were subtended the distinctive floating leaves of Little Floating Heart (Nymphoides cordata). None of our Field Guides had included the basal leaves, which is why we were all stumped!
Mystery solved! Very satisfying, indeed.