Potamogeton cheesemanii

The rhizomes root at nodes, and produce long branches with few leaves. The leaves take two shapes: those underwater are longer and translucent, while the ones that float are oval and opaque. The flowers, a dense spike, float, although they submerge when they begin to fruit. The flowers are cream, red, or pink.^[2][4] The species flowers from November to February, and fruits from December to March.^[5]

This species can be told from Potamogeton suboblongus by the dimorphic leaves, and from P. ochreatus by its well separated longitudinal nerves.^[4]

The biomass of this plant varies seasonally, with less biomass found in the winter months than in the summer and spring.^[6] While height-restricted, P. cheesemanii is one of the taller plants in native hydrophyte communities.^[7]

This species is found across New Zealand, on all of the major islands including the Chatham Islands, and some of the minor islands such as Great Barrier.^[8] It also grows in southern Australia and Tasmania,^[2][4][9] although at least one authority considers it endemic to New Zealand.^[3]

Macrofossils of P. cheesemanii seeds have been found from the Aranuian era in Canterbury, roughly 14k-10k ybp.^[10]

Potamogeton cheesemanii grows on slow rivers, ponds, lakes, and ditches. It grows from the coast to the montane areas.^[4] They can grow in tarns at at least 1000 m in elevation.^[11]

Potamogeton cheesemanii is associated with some macroinvertebrate communities, but not as many as other native hydrophytes according to at least one study.^[12] Some attempts at using Grass Carp to eat pond weeds has found that they will eat P. cheesemanii, but generally prefer other plants.^[13]

Multiple species of dragonfly lay their eggs on the leaves.^[14]