Observations of Podostemum ceratophyllum Michx., an Endangered Riverine Plant in Ohio

The angiosperm Podostemum ceratophyllum (Hornleaf Riverweed) (Podostemaceae) is native to the montane and Piedmont regions of eastern North America where it grows submerged in swift-water riverine habitats. Ecologically, Hornleaf Riverweed provides habitat for aquatic invertebrates and fish, and is grazed on by a variety of consumers, including geese, turtles, and crayfish. Only 1 population has been documented in the state of Ohio, in the Grand River (Ashtabula County). Hornleaf Riverweed is listed as endangered in Ohio. The lone Ohio population was last surveyed 24 years ago (September 2000). Here, I document the status of this unusual aquatic species of conservation importance in Ohio.