Spiny Quillwort: Isoetes echinospora
- Description of this shallow water species, sometimes known as Isoetes setacea, and two photographs.
- http://www.plant-identification.co.uk/skye/isoetaceae/isoetes-echinospora.htm

Quillwort: Isoetes lacustris
- The characteristics of this aquatic species with two photographs.
- http://www.plant-identification.co.uk/skye/isoetaceae/isoetes-lacustris.htm

ODU Isoetes Page
- Comprehensive resource on quillworts from Old Dominion University.
- http://www.odu.edu/webroot/instr/sci/plant.nsf/pages/isoetes

Isoetes hyemalis D.F.Brunt.
- Taxonomic data and mapped distribution of this quillwort from Atlas of Florida Vascular Plants.
- http://www.plantatlas.usf.edu/main.asp?plantID=3001

Isoetes flaccida Shuttlew. ex A.Braun
- Taxonomic data and mapped distribution of this quillwort from Atlas of Florida Vascular Plants.
- http://www.plantatlas.usf.edu/main.asp?plantID=2508

Isoetes boomii Luebke
- Taxonomic data and mapped distribution of this quillwort from Atlas of Florida Vascular Plants.
- http://www.plantatlas.usf.edu/main.asp?plantID=2632

Isoetes appalachiana D.F.Brunt. & D.M.Britton
- Taxonomic data and mapped distribution of this quillwort from Atlas of Florida Vascular Plants.
- http://www.plantatlas.usf.edu/main.asp?plantID=3045