Plants in the worldwide, but especially northern temperate Buckwheat Family (Polygonaceae) are annual, biennial, and perennial herbs, subshrubs, shrubs, trees, vines, and lianas with simple, entire, alternate, opposite, or whorled leaves, flowers with 2 to 6 tepals and a superior ovary, and fruit in the form of an achene.

Listed below are some of the southeastern Arizona plants in this family.