Potamogeton diversifolius Raf.:Variable-leaf pondweed, waterthread pondweed. Potamogetonaceae (pondweed family).
Native perennial. Found in shallow slow-moving or still water, where thread-like rhizomes produce stems to 4.5 ft (1.4 m). This is one of the smaller pondweeds to have floating leaves and these differ from the submersed leaves in shape. Leaves are generally arranged alternately on the stem, although they can arise so close together as to look opposite. Submersed leaves are extremely narrow, thread-like, to 2.4 in (6 cm) long, and taper to a sharp bristle-like point. Floating leaves are leathery, oval to elliptical, slightly wedge-shaped or tapering at the base and tapering or rounded at the tip, to 1.6 in (4 cm) long; these leaf stalks are slender and up to 1 in (2.5 cm) in length. Stipules are present on both types of leaves and are partially attached to the base of the leaf stalk; those on floating leaves are prominent, 0.75 - 1 in (2 - 2.5 cm) long. Flowering spikes are borne at nodes of both floating and submersed leaves; the former spikes are more club-like, the latter shorter and more spherical.
