Coefficient of Conservatism:
Coefficient of Wetness:
M. R. Penskar
Lakes, ponds, quiet rivers and streams.
The most reliable character for distinguishing it from N. advena, especially for use with herbarium specimens, is the flattened (or even narrowly winged) petiole. The leaves (except for submersed basal ones) of N. variegata usually have the blades floating, with basal lobes ± parallel, the sinus narrow, parallel-sided, or closed (the lobes slightly overlapping). In N. advena, the blades are often erect, held above the water (the plant thus perhaps better adapted for emergence on drying shores), with basal lobes rather divergent, the sinus wide-angled (often as much as 60° or even more). In N. variegata the lobes are frequently divergent, and in N. advena they are more rarely overlapping. Leaf aspect is thus more helpful in the field, when other characters can be considered, than in the herbarium, where the round or 2-edged petiole shape seems most helpful.