Potamogeton sachalinensis Potamogeton perfoliatus subsp. richardsonii Potamogeton perfoliatus var. richardsonii Potamogeton perfoliatus var. sachalinensis Potamogeton perfoliatus var. lanceolatus Spirillus perfoliatus var. richardsonii
World Flora Online, http://www.worldfloraonline.org/, accessed June 20, 2024