[1] Species of Pteroxygonum are twining vines growing from a large woody globe-shaped tuber.
Their leaves are broad and palmate, with a dark red mark around each primary leaf vein.
They separated Pteroxygonum from Polygonum on the basis of the "very notably different structure of the fruit".
A 2015 molecular phylogenetic study found that the species formerly called Polygonum denticulatum was closely related to Pteroxygonum giraldii, and accordingly moved it to Pteroxygonum.
[2] Oxygoneae Persicarieae Fagopyreae Pteroxygoneae (Pteroxygonum + some Fallopia) Calligoneae Rumiceae Polygoneae As of March 2019[update], Plants of the World Online accepted two species:[1]