Myriophyllum rubricaule Valk. & Duist. sp. nov. 

Diagnosis: Herba perennis aquatica vel paludigena. Folia omnia verticillata pectinata. Flores unisexuales, solae plantae femininae culturaeque cognitus. Flores intra axillas foliorum solitarii. Planta valde similaris Myriophyllo aquatico, sed caules foliaque modice, caules purpurei et folia emergentia virida. Flores feminei subrosei

Etymology: The species epithet is based on the purplish red color of the stem.