Jointweed

noun

1. Polygonum articulatum, an American plant: so called from its many-jointed spike-like racemes.
2. A. name of a species of Equisetum.
3. The mare's-tail, Hippuris vulgaris.
4. A slender, nearly leafless, American herb (Polygonum articulatum), with jointed spikes of small flowers.
5. Any member of the genus Polygonella of knotweeds and smartweeds.