In Britain the family Potamoganaceae (the Pond weed family) are dicotyledons, with a reduced preianth.
Leaves either opposite or alternate Inflorescence in stalked spikes; Flowers with 4 perianth segments Stamens 4 Genera eg. Groenlandia, Potamogeton |
Potamogeton | Leaf margin | Petiole | ||
toothed | entire | hinged | not hinged | |
P. crispus | X | X | ||
P. natans | X | X | ||
P. polygonifolius | X | X |