Smartweed grows in freshwater marshes and low places, including those at Hagerman National Wildlife Refuge. The seeds provide fine dining for waterfowl. According to NPIN, Ladybird John WildflowerCenter, there are about 75 species of Smartweed in the US. Smartweed is in the genus Polygonum and is native in the U.S., including Alaska, and in Canada.
|Smartweed at HNWR, by Dick Malnory|
From a website on Texas duck hunting, we learn that
…various Smartweed species colloquially known as Smartweed, Knotweed, Ladysthumb, Bindweed, Tearthumb or Bistort, can be very difficult to identify by specie, as they appear very similar and will hybridize with one another. The ones of most interest to duck hunters [and to ducks!] all have very pale pink (almost white) to deep pink clusters of flowers at the terminal end of multiple flower spikes. All have long, rather thin leaves. All have a ring formed around the stalk where the leaf stem joins the stalk, and the stalk bends at each of these many junctures. These bends somewhat look like knees, and give the plant its genus name. Literally translated, Polygonum means; many knees.
The flowers of the various species may be greenish white, white or pink. Some species are annual and some perennial. One perennial species is described at http://aquaplant.tamu.edu/plant-identification/alphabetical-index/smartweed/ and is commonly known as Water Pepper. A common species, Pennsylvania Smartweed, is annual and is described at http://plants.usda.gov/core/profile?symbol=POPE2.
According to a commercial site for Pennsylvania Smartweed:
The nectar of the flower attracts many different insect species including long and short-tongued bees, small butterflies and moths. In addition it is an excellent food for waterfowl including ducks, geese, doves, and other game and non-game species. Furthermore, the dense foliage provides excellent cover for immature waterfowl, marsh birds, and wintering pheasants.