Paddling around the big island in the Carmans river I came across the Blue Water or Blue Flag Iris. What a delightful surprise. They grow at the water's edge in clumps like they were placed there by a gardener.
Blue Water Iris (Iris Versicolor) are perennials native to North America. Their rhizomes, (roots) are poisonous to humans and animals.
info on wikipedia .... https://en.wikipedia.org/wiki/Iris_versicolor