Polygonum gracile is a scientific name that has been published six times and is considered botanical synonym of five species of plant:
Fagopyrum esculentum (cultivated buckwheat), synonym published in 1855 by Carl Meissner Persicaria hydropiper, synonym published in 1796 by Richard Anthony Salisbury Persicaria hydropiper, synonym published in 1810 by Robert Brown (1773–1858) Persicaria posumbu subsp. posumbu, synonym published in 1865 by Friedrich Anton Wilhelm Miquel Polygonum bellardii, synonym published in 1855 by Giovanni Gussone Polygonum tenerum, synonym published in 1818 by Thomas Nuttall