Common names: Yellow floating heart, fringed water lily
Nymphoides peltata is an aquatic perennial with long, underwater stolons which establishes itself in slow-moving fresh water. It has small yellow flowers and flat leaves. It has invaded our water system and is usually removed annually, but comes back with a vengeance. It is listed in the Plant Collection record as of 2000, but curatorial staff don't know if it was intentionally planted.
More about water lilies in the Sept. 4, 2020 Garden Story.
Flower photo by Radio Tonreg, Austria / CC (https://creativecommons.org/licenses/by/2.0)
Pond photo from Roy Forster Cypress Pond