Rupturewort

Description

Polygonum�is a�genus�of about 220 species of�flowering plant�in the buckwheat and knotweed family�Polygonaceae. Common names include�knotweed,�knotgrass,�bistort,�tearthumb,�mile-a-minute,�smartweed�and several others. In the�Middle English�glossary�of�herbsAlphita�(c.�1400�1425), it was known as�ars-smerte.�There have been various opinions about how broadly the genus should be defined. For example,�buckwheat�(Fagopyrum esculentum) has sometimes been included in the genus as�Polygonum fagopyrum.