polygonum

noun

any polygonaceous plant of the genus Polygonum, having stems with knotlike joints and spikes of small white, green, or pink flowersSee also knotgrass, bistort, prince's feather (def. 2)

Word Origin for polygonum

C18: New Latin, from Greek polugonon knotgrass, from polu- poly- + -gonon, from gonu knee
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