Late in the summer, dense rose-colored spikes of Ladysthumb Knotsweed may be seen in lakes, beaver ponds or slow moving streams. These clusters of flowers have reminded some visitors of a painted fingernail. This plant is a perennial with floating or submerged stems. Each flower has from 4 to 6 sepals and from 4 to 9 stemens. The leaves are oblong-elliptic, smooth and from 2 to 4 inches long. As the scientific name (Polygonum amphibium) implies it is at home on land or in the water; however, this form is usually aquatic. {Plants of Yellowstone and Grand Teton National Parks by Richard J. Shaw pg 116}