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.Idaho Mountain Wildflowers

The Buckwheat Family, Polygonaceae

The name, Polygonaceae, is derived from two Greek words; poly meaning “many” and goni for “joint”, a reference to species that have swollen stem-nodes or joints.* The family is made up of fifty-two genera and approximately 1,105 species. Typically, members have smooth-bordered, unlobed leaves and flowerheads made up of tight clusters of small flowers. Varying numbers of sepals (three to six) substitute for petals. In some species an accessory structure known as an “ocrea” forms a sheath around the main stems at the node where the leaves join it. A few Polygonaceae are commercially important as ornamentals and as food plants, including buckwheat (Polygonum esculenta), sorrel (several Rumex species) and rhubarb (Rheum rhaponticum). The latter—in common with other members of the family—contains oxalic acid responsible for the plant’s acidic juice. Other species of rhubarb (e.g., Rheum officinale) were used in the past as purgatives, and a few species have found a place in ornamental gardens.

*This derivation is debated. Some believe that the gon- stem refers to “seeds” rather than “joints.” Thus Polygonaceae would imply “many seeds.

The Wild buckwheats, Eriogonum spp.

Eriogonum is by far the largest genus of Polygonaceae, made up mostly of western North American plants. The number of species in the genus is outnumbered only by the number of penstemons (Penstemon spp.) and the milk vetches (Astragalus spp.). As with those plants, identification of wild buckwheats is often difficult, made more so by hybridization, and variations in form and color.

Sulphurflower wild buckwheat, Eriogonum umbellatum Torr. var. ellipticum (Nutt.) Reveal (left). The sulphurflower wild buckwheat is sometimes known as the “umbrella buckwheat,” possibly a better name for it reflects the species name umbellatum (Latin for “umbrella”)  reminiscent of the umbels that characterize the parsley family (Apiaceae). Highly variable, there are some forty varieties. The variety shown here has a branched umbellate inflorescence. Another variety, with cream-colored flowers and a simple umbel, var. dichrocephalum Gandoger, is also common in our mountains.

Parsnip-flower wild buckwheat, Eriogonum heracleoides Nutt. (right). This is a montane plant that sometimes grows in profusion as a  dominant valley wildflower in the dry heat of early summer. Off-white flower heads and a whorl of bracts located mid-stem below the creamy-white flowerhead, serves to identify the plant.

Purple cushion wild buckwheat, Eriogonum ovalifolium Nutt. var. purpureum (Nutt.) Durand (left). The purple cushion wild buckwheat is characterized by small, oval, gray-green leaves, a large, tightly formed flowerhead and creamy white flowers that develop purple coloration as they mature--just starting to occur in ths image--explaining the varietal name purpureum; it is only one of many varieies of this species.

Dwarf cushion wild buckwheat, Eriogonum ovalifolium Nutt. var. depressum Blank. (right). The dwarf cushion wild buckwheat is native to the northern Rocky Mountains where it grows as a subalpine / alpine plant. When mature, its flowers are often the bright red shown in the illustration. The cushion buckwheats shown here are two of eleven varieties of Eriogonum ovalifolium.

Piper's wild buckwheat, Eriogonum flavum var. piperi is another plant that grows in clumps. It is characterized by bright  yellow flower heads. The leaves are usually larger and greener than those of the cushion buckwheats. Piper's wild buckwheat is common from mid-elevations to alpine slopes. Several varieties are recognized, those of Idaho's mountains are var. piperi as shown here. The species name flavum means "yellow." Many eriogonums have brightly colored flowers and, since their color persists, and they hold up well after they are gathered, they are sometimes used as dried plants.

Hairy Shasta wild buckwheat Eriogonum pyrolifolium Hook. var. coryphaeum Torr. & A. Gray (left). A high altitude plant, the alpine wild buckwheat grows near treeline, where it blooms soon after snow-melt. Identify it by its smooth, bright green basal leaves and white flowerheads. It is native to the high mountains of all four states of the Northwest.

Hitchcock’s wild buckwheat, Eriogonum capistratum Reveal (left). Hitchcock’s wild buckwheat is an eye-catching, matted plant made up of tightly clustered tiny gray leaves and two-tone yellow and red flowers. This variety occurs in the foothills and lower mountains of central Idaho. An alpine variety, var. muhlickii, is found in the high mountains of western Montana

Mat Buckwheat, Eriogonum caespitosum Nutt. (right) forms dense, little-leaved mats with unbranced stems that have the terminal flowerheads typical of wild buckwheats. It ranges from southeast Oregon and adjacent California across central Idaho to Montana, Wyoming and Colorado

Broom (or wicker-stem) wild buckwheat, Eriogonum vimineum Dougl. ex Benth. (left, right).  While most eriogonums have rounded flowerheads, like those shown above, a few have flowers that grow along the plants' stems. An example is shown here. The broom wild buckwheat is a low, weedy plant with brownish-red, brittle stems arising from a basal rosette of leaves; these are usually dead and dried-up by the time the flowers appear. The tiny white and rose colored flowers, greatly magnified here, emerge from tubular involucrums along the plants' branching stems. The plants, although seldom noticed, are not uncommon. They are found in Idaho, Nevada, and the three Pacific coast states. The Latin species name, vinimeum, means "flexible stems"

Sorrels or Docks, Rumex spp..

Mountain sheep sorrel, Rumex paucifolius Nutt. (left, right). The mountain sorrel’s clustered off-white flowers turn conspicuously red as they fruit so the plants form red patches in mountain meadows where they grow. The name, paucifolius, means “few-leaved,” pertaining only to the flower-bearing stems, for the plants have many lance-shaped basal leaves. Rumex is the Latin word for “sorrel.” The genus also includes the edible sorrel, Rumex acetosa (not shown), whose acidic taste is derived from the oxalic acid common to the leaves of all species of Rumex. Our plants are unrelated to wood sorrels (Oxalis spp., Oxalidaceae) whose foliage also contains oxalic acid.

Willow dock, Rumex salicifolius Weinm. var. triangulivalvis (Danser) J.C. Hickman (left, right). Six (of seven) varieties of this plant are found in the Northwest. The one shown here is restricted to high elevations in the northern Rocky Mountains. The name, salicifolius, means “willow-like leaves.” At first glance, it is not an especially attractive plant, although the flowers and the fruit (“achenes,” shown on the right) are rather striking. Willow dock is considered a weed in much of its range, but our plant grows too high to have a weedy impact on anything. The varietal name, triangulivalvis refers to the form of the plant’s fruit.

Poke knotweed, Polygonum phytolaccifolium Meisn. ex Small (left, right). The poke knotweed, variously known also as the alpine knotweed, pokeweed, or fleeceflower, bears some slight resemblance to the common pokeweed (Phytolacca americana, Phytolaccaceae), and its species name, phytolaccifolium, implies that its leaves resemble pokeweed leaves. The poke knotweed is a common subalpine plant found in moist situations where it blooms from mid-summer on. Given its distinctive appearance, it is easy to identify. While it is without food value for humans, animals graze freely on the plant.

American bistort, Bistorta bistortoides Pursh (left, right). The American bistort grows in mountain meadows throughout the West. "Bistort" is an old name, from the Latin bis (twice) and torta (twisted) referring to the plants’ twisted roots and first applied to a similar Eurasian plant. Recent genetic studies suggest that our plant, formerly classified as Polygonum bistortoides, deserves to be in its own genus, or in that of the Eurasian bistort, as we have done here. The plant blooms from June well into August. Small white flowers form well delineated clusters at the top of spindly stems (right). Both the roots and the young leaves of the bistort were used as food by Native Americans. Deer graze on the flowers and foliage, and bears dig up the bulky roots. Lewis and Clark were the first to collect this plant, on the Wieppe Prairie in north central Idaho (June 12, 1806). The illustration on the left shows white American bistort, interspersed with bright orange Indian paintbrush, growing above treeline at the foot of Old Hyndman Peak, in south-central Idaho's Pioneer Range.

Alpine bistort, Persicaria bistorta (L.) Samp. (formerly Polygonum viviparum L. var. Wahlenb. and Bistorta vivipara [L.] S. F. Gray).  This little streamside and meadow plant, now in genus Persicaria, grows in our Northwest and in the western mountains of the United States and Canada. Its range extends northward and it is found in northern lands and mountain ranges throughout the Northern Hemisphere. White or pink flowers are borne at the top of long stems that arise from a cluster of narrow, basal leaves. Small "bulbils" are borne below the flowers. These form leaves and then fall off as ready-made plantlets--the alpine bistort's chief mode of reproduction. As often occurs with widely distributed plants, this one has a long list of common names; including some related to its use in making "Lent-" or "dock-pudding" in Northern England. A large, showy cultivar of the plant is used in ornamental gardens.

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