| Parent | Category | Figures | |
|---|---|---|---|
| 1 | Hydrophyllum | virginianum | 1068 |
| 2 | Hydrophyllum | canadense | 195 |
| 3 | Hydrophyllum | capitatum | 194 |
| 4 | Hydrophyllum | appendiculatum | 181 |
| 5 | Hydrophyllum | tenuipes | 178 |
| 6 | Hydrophyllum | occidentale | 85 |
| 7 | Hydrophyllum | macrophyllum | 54 |
| 8 | Hydrophyllum | fendleri | 43 |
| 9 | Hydrophyllum | alpestre | 31 |