<i>Callitriche heterophylla</i> Pursh - twoheaded water-starwort
Mark Mohlenbrock, Wetland flora: Field office illustrated guide to plant species. USDA Natural Resources Conservation Service. Provided by NRCS National Wetland Team, Fort Worth, TX.
1992
<a rel="nofollow" class="external text" href="https://plants.usda.gov/gallery/pubs/cahe3_004_pvd.tif">USDA-NRCS PLANTS Database / USDA NRCS. Wetland flora: Field office illustrated guide to plant species. USDA Natural Resources Conservation Service.</a>