Buckwheat Family

Naked-stemmed Buckwheat © AFengler

Polygonaceae (pol-i-go-NA-see-ee)

Iconic Features

    • Swollen stem joints
    • Dense clusters of tiny flowers
    • Triangular seeds

    Description (Jepson)

      • Mostly herbaceous plants
        • Annuals, perennials, and shrubs
      • Eudicotyledons (eudicots) – a major lineage of flowering plants including most plants traditionally described as dicots and generally characterized by
        • 2 seed leaves (dicotyledon)
        • Netted (reticulate) leaf venation
        • Flower parts in fours and fives
        • Pollen grains with 3 pores (tricolpate)
        • Vascular bundles in stem arranged in a ring
        • Taproot system
      • Stem nodes (joints) often swollen
        • Generally with a scarious sheath around the stem
          • Formed by the fusion of papery stipules (leaf-like structures at the base of the leaf stalk), called ochrea
      • Leaves
        • Simple (not divided into leaflets) and entire (with smooth edges)
        • Usually alternate (1 leaf at each junction with stem)
        • Attached to stem nodes or basal
        • Sometimes with papery stipules
      • Flowers
        • Inflorescence (flower arrangement) in a variety of dense clusters
        • Tiny, generally bisexual, radially-symmetric flowers
          • 2-3 petals and 2-3 sepals (outer flower parts), in 2 separate whorls, similar in appearance and collectively called tepals
          • May be green, cream, white, yellow, pink, or red
            • Tepals often persist and age to red or brown
        • Sometimes held in cup- or vase-shaped bracts (modified leaves at flower base)
        • Ovary superior (above the attachment of other flower parts)
      • Fruit is an achene (a single-seeded, dry fruit that does not split open), usually 3-angled
        • Sometimes with thin, flat margins (wings), which aid in dispersal by catching a ride on a breeze


        • Approximately 1,200 species, mostly in the northern hemisphere
          • Includes rhubarb, docks, sorrels, and buckwheats
          • Many species adapted to high elevations and dry, cold climates
        • Many species are astringent or highly toxic due to tannic and oxalic acids and anthraquinone glycosides
          • Stems of rhubarb (Reum rhabarbarum) are edible, but the leaves contain toxins, e.g. oxalic acid, which can cause kidney damage
        • Buckwheats in the genus Fagopyrum have been cultivated for thousands of years for use as pseudocereals
          • Common crop in the US before nitrogen fertilizer in the 20th century allowed corn and wheat to become dominant (Myers 2018)
          • Flour used for noodles, like soba, in many Asian cuisines and for traditional Russian blinis, French crepes, and Dutch pancakes
          • Hulled, unground seeds, a type of groats, are used for porridge
          • Accommodate some dietary or cultural restrictions that prohibit the eating of wheat
        • Scientific name from the Greek poly, “many,” and gónato, “knee,” referring to the swollen stem nodes (joints) characteristic of this family
        • Common name from Old English for “beech-wheat”
          • 3-sided seeds resemble beechnuts
          • Though not related to wheats, which are in the Grass family, the seeds of some buckwheats are ground into meal or flour
          • Also known as the Knotweed family
        • Represented by 11 species at Edgewood

        See General References

        Specific References

          Myers, R. 2018, Dec. Growing Buckwheat for Grain or Cover Crop Use. Extension: University of Missouri.

          Browse Some Edgewood Plants in this Family