Distribution:  Mostly centered in Northern and temperate parts of the World.  The Texas flora includes 8 genera, 69 species and 22 infraspecific taxa..

Floral structure:

Significant features:  Most species of this family, with the exception of the large genus Eriogonum (false buckwheat) show a unique vegetative feature at the node.  A modified stipule encloses the node for form a sheathing structure known as an ocrea.  The nodes also (like the Caryophyllaceae) tend to be swollen and this feature is signaled by the Genus name Polygonum which translates to 'many kneed', a reference to the swollen nodes.  The flowers are small, perfect (usually) and either show a bi- or uniseriate calyx that often continues to develop after anthesis (accrescent) to produce a winged enclosure for the fruit, a trigonal (three-sided) or lenticular (lens shaped) achene.
 

Polygonum - nodes and ocrea	Node of a sea grape (Coccoloba uvifera) with ocrea	Eriogonum longifolium (the largest genus with 250 species) - flowers  (rare item)	Rheum officinale from Kohler's Medicinal Plants

More information on the Polygonaceae or Phoradendron (campus wild plant -Mistletoe) - Also (Fall flora) Polygonum hydropiperoides vs. P. bicorne