Curly-leaf Pondweed (Potamogeton crispus): a Non-Native Aquatic Plant in New Jersey Waterways
Curly-leaf pondweed is a hardy perennial submersed aquatic plant. Attached to the lake or pond bottom by rhizomes, it can grow to reach the lake surface by mid-spring (Fig. 1). It has a very distinctive appearance with crinkled leaves and finely toothed edges that alternate along the lighter colored and flattened stem (Fig. 2). The oblong, light to dark green leaves are wavy resembling lasagna noodles up to 7½ cm (3 in) long. In spring, curly-leaf pondweed can produce flower spikes that rise above the surface. The small flowers are arranged in a dense terminal spike on a curved 1–2 cm (1/3–3/4 in) stalk, however the main methods of spreading are not by seed, but by asexual stem growth from the perennial rhizomes and reproduction by vegetative structures called turions. Turions are dormant buds that develop in leaf axils (the “joint “or space where the leaf stem and the stalk of the plant come together), or are present at the tip of short branches (DiTomaso, et al. 2013). They are made up of several overlapping modified leaves resembling small greenish-brown pinecones, and are produced in great numbers by the start of summer.