Monographs Details: Potamogeton foliosus Raf. var. foliosus
Authority: Haynes, Robert R. & Holm-Nielsen, Lauritz B. 2003. Potamogetonaceae. Fl. Neotrop. Monogr. 85: 1-52. (Published by NYBG Press)
Synonyms:Potamogeton pauciflorus f. major Pursh, Potamogeton foliosus var. macellus Fernald, Potamogeton niagarensis Tuck., Potamogeton pauciflorus Morong, Potamogeton curtissii Morong
Description:Variety Description - Ligules greenish to brown, delicate to slightly fibrous, the veins decaying with age. Glands rare, when present to 0.3 mm diam. Spikes mostly continuous. Fruits olive to green-brown, 1.5-2.7 x 1.2-2.2 mm; keel mostly 0.2 mm high or higher; beak 0.2-0.6 mm long.

Discussion:The species is most similar to Potamogeton pusillus by the linear submersed leaves, ligules that are free from the leaf blade, and absence of floating leaves. In vegetative condition, the two species are difficult to separate. They are readily separated in fruit, however, as the fruits of P. foliosus are abaxially keeled whereas those of P. pusillus are rounded abaxially.
Distribution:Mexico North America| Baja California Mexico North America| Baja California Sur Mexico North America| Chihuahua Mexico North America| Guanajuato Mexico North America| Jalisco Mexico North America| México Mexico North America| Michoacán Mexico North America| Puebla Mexico North America| Sonora Mexico North America| Querétaro Mexico North America| Veracruz Mexico North America| Guatemala Central America| Escuintla Guatemala Central America| Suchitepéquez Guatemala Central America| Costa Rica South America| Cuba South America| Cienfuegos Cuba South America| La Habana Cuba South America| Matanzas Cuba South America| Villa Clara Cuba South America| Jamaica South America| Cornwall Jamaica South America| Jamaica South America| Jamaica South America| Haiti South America| Dominican Republic South America| San Juan Dominican Republic South America| La Vega Dominican Republic South America| Puerto Rico South America| Aguadilla Puerto Rico South America| Aguas Buenas Puerto Rico South America| Coamo Puerto Rico South America| Lares Puerto Rico South America| Peñuelas Puerto Rico South America| Virgin Islands South America| Saint Thomas Virgin Islands of the United States South America|