Definition of polygonum in US English:

polygonum

noun

  • A plant of a genus that includes knotgrass and knotweed, some of which are weeds and some are garden ornamentals.

    Genus Polygonum, family Polygonaceae

    • ‘Most of the starchy grains that are present at Langford sites are either wild chenopod or polygonum seeds.’
    • ‘‘I love how it grows into the polygonum,’ Julie says.’
    • ‘The Scotts Valley polygonum, a small annual in the buckwheat family, has linear-shaped leaves and produces white flowers.’
    • ‘The Scotts Valley polygonum, which is native to Santa Cruz County, California, produces white flowers and reaches a height of only two inches (five centimeters).’
    • ‘Also on February 15, 310 acres in Santa Cruz County were proposed as critical habitat for the Scotts Valley spineflower (Chorizanthe robusta var. hartwegii) and the Scotts Valley polygonum.’

Origin

Modern Latin, from Greek polu- ‘many’ + gonu ‘knee, joint’ (because of the swollen joints sheathed by stipules).

Pronunciation

polygonum

/pəˈliɡənəm/