Northern Prairie Wildlife Research Center
Reference:
Rossbach, C. B. 1939. Aquatic utricularias. Rhodora 41:113-128.
| Lead | Characteristic | Go To |
| 1 | Ultimate leaf segments flat, nearly to fully as wide as the primary ones, with a distinct midvein; lower lip of the corolla about 2X as long as the upper. | Lead 2 |
| 1 | Ultimate leaf segments filiform, the segments progressively narrower in successive branchings; lower lip of the corolla little if any longer than the upper. | U. vulgaris |
| 2 | Bladders borne on specialized branches distinct from the dissected leaves; leaf segments spinulose-toothed. | U. intermedia |
| 2 | Bladders borne on ordinary leaves; leaf segments entire, sometimes toothed at the tip. | U. minor |