| Numerous sterile quillwort hybrids with abortive spores exist, and in some cases these hybrids have regained fertility through a process of chromosome doubling. |
| Bolander's quillwort is a plant whose only known locations in Canada are in Waterton Lakes National Park. |
| Engelmann's quillwort, Isoetes engelmannii, an addition to the Flora of Canada. |
| The lowest quillwort diversity is found in permanent ponds and streams of the Appalachian Mountains. |
| Like ferns, quillwort reproduces by spores. |
| The other is a quillwort, or Isoetes, which reproduces through male and female spores and thus is considered more closely related to ferns than to flowering plants. |
