
Polygonaceae (pol-i-go-NA-see-ee)
Iconic Features
- Swollen stem joints
- Dense clusters of tiny flowers
- Triangular seeds
Description (Jepson)
- 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
- Mostly herbaceous plants
- Annuals, perennials, and shrubs
- 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
- Generally with a scarious sheath around the stem
- 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
- Sometimes held in cup- or vase-shaped bracts (modified leaves)
- 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
- Ovary superior (above the attachment of other flower parts)
- Inflorescence (flower arrangement) in a variety of dense clusters
- 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
Notes
- 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
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
