In Our Backyard: Toothcup


Toothcup (Rotala ramosior) is a charming, low-sprawling plant that is a rare, but fascinating find in the Thompson-Nicola Watershed. Blooming from June to October, toothcup flowers range from white to pink and ladder up the plant’s elongated leaves along the stem. As the flowers develop into fruits, they transform into bright red bulbs making it more recognizable to the eye.


Toothcup is an uncommon species that occurs in open, seasonally wet areas where water levels fluctuate such as in riverbanks, ditches, and muddy shores. The plant has only been identified in two areas in British Columbia: The Thompson-Nicola Watershed and the South Okanagan Valley. In the Thompson-Nicola Watershed, toothcup has specifically been identified along the sandy and silty shores of the Thompson River and Kamloops Lake.


Toothcup is a Red-listed, or endangered, species in British Columbia, and in the South Okanagan Valley subpopulation, the introduction of grasses to the area is projected to disrupt the survival of toothcup in the coming years. Threats to toothcup include:

  • introduction of invasive plants
  • shoreline development
  • shoreline impacts of recreational activities
  • water level manipulation
  • agriculture

Image: Toothcup by Kevin Faccenda, licensed under CCO 1.0

Conservation Efforts

Currently, there is no specific provincial legal protection for toothcup in BC. As habitat quality continues to deteriorate due to shoreline disturbance, changes to flood dynamics, and loss of habitat from invasive species, toothcup shifts closer to becoming more at-risk in BC. As one of two of the subpopulations in BC, the Thompson-Nicola Watershed should be doing all it can to preserve this native plant. Actions we can take to help toothcup include:

  • keeping the identified toothcup locations free of invasive weeds;
  • avoiding trampling or driving over toothcup and the surrounding habitat;
  • learning more about toothcup and its biology; and
  • if you have livestock near a toothcup habitat, installing protective fencing around the plants.

Additional Resources

Featured image: Toothcup by calloftheloon, licensed under CCO 1.0