Habitat: Large-leaf pondweed grows in the submersed plant community. It is found in soft sediments where the water is quiet, in depths up to several meters.
Description: Large-leaf pondweed is a large, stately plant, with two distinct leaf types. The submersed leaves (3 to 7 cm wide) are the broadest of any pondweed in Maine. The many veins of these supple, translucent leaves are easy to see when held to the light. The leaves are often gracefully arched, with the outer margins folding slightly toward one another at the midvein. They are alternately arranged on robust stems, attached by leaf stalks that vary in length from 1 to 6 cm. The floating leaves are slightly smaller (2.5 to 5 cm wide), more oval-shaped, and not translucent. They generally occur in opposite pairs at the top of the plant, also attached to the stem by leaf stalks. The stalks of the floating leaves are generally quite long (up to 30 cm). The stipules of both leaf types are large (3.5 – 12 cm long), largely free from the stem, and tapering to a sharp point. The flowers, followed by fruit, occur among the floating leaves and are densely arranged on an emergent spike. The individual fruits are oval to egg-shaped with a small beak protruding from a point along the outer rim.
US Range: Large-leaf pondweed is native |
