Potamogeton vaseyi J.W. Robbins

Vasey's Pondweed

• State Rank: S2
• Global Rank: G4
• State Status: Special Concern

Habitat: Quiet muddy or calcareous waters. [Open water (non-forested, wetland)]

Range: Quebec to Wisconsin, south to southern New York.

Aids to Identification: Pondweeds are aquatic, perennial herbs with reduced, inconspicuous flowers, which in many species, are elevated above the surface of the water. Potamogeton vaseyi has dimorphic leaves: very narrow (0.2-1 mm wide), flaccid, submersed leaves and wider, thicker floating leaves. This species, like the common P. spirillus, has small floating leaves, only 0.6-1.5 cm long for P. vaseyi. Small spikes (3-8 cm tall) and stipules that are distinct from the leaf blade will serve to separate P. vaseyi from other species of pondweeds in Maine.

Ecological characteristics: Ecological relationships in Maine are not well known.

Phenology: Flowers July - August.

Family: Potamogetonaceae

Synonyms: Potamogeton lateralis Morong, pro parte.

Known Distribution in Maine: This rare plant has been documented from a total of 17 town(s) in the following county(ies): Androscoggin, Aroostook, Cumberland, Franklin, Hancock, Kennebec, Penobscot, Somerset.

Reason(s) for rarity: Scarcity of habitat.

Conservation considerations: Unknown.