Plant of the Week

Map of the United States showing states. States are colored green where Sacajawea’s bitterroot may be found.
Range map of Sacajawea's bitterroot. States are colored green where the species may be found.

Sacajawea’s bitterroot compared to the size of a U.S. quarter.
Sacajawea's bitterroot (Lewisia sacajaweana). Photo courtesy of Edna Rey-Vizgirdas.

Sacajawea’s bitterroot.
Sacajawea's bitterroot (Lewisia sacajaweana). Photo courtesy of Edna Rey-Vizgirdas.

Sacajawea's bitterroot (Lewisia sacajaweana)

By Edna Ray-Vizgirda

Statue of Sacajawea and child at the Sacajawea Center

A species new to science, Sacajawea's bitterroot (Lewisia sacajaweana), is the first plant species to be named in honor of Sacajawea.

An Idaho native, this rare and beautiful plant occurs nowhere else in the world but central Idaho. Just over two dozen populations of Sacajawea's bitterroot are known to exist, roughly three-fourths of them on the Boise National Forest. Scattered populations also occur on the Payette, Sawtooth, and Salmon-Challis National Forests.

A high country resident, Sacajawea's bitterroot can be found in montane and subalpine habitats ranging from 5,000 to 9,500 feet. The plant is dormant most of the year, like its relative, the common bitterroot, Lewisia rediviva (Montana's state flower). Shortly after snowmelt, a rosette of succulent leaves emerges, followed by showy white flowers that hug the ground. After flowering, all aboveground signs of the plant disappear, with the tuberous carrot-like root hidden just below the surface.

The name Lewisia was originally developed in 1813 by botanist Frederick Pursh to honor Meriwether Lewis. Although Lewis collected a handful of bitterroot plants during the historic journey, Sacajawea's bitterroot was apparently not one of them.

Sacajawea's bitterroot was not always considered a unique species. It was originally known as Kellogg's bitterroot, also found in California's Sierra Nevada Mountains. Recent research regarding the plant's genetic and physical characteristics confirmed that the Idaho plants are indeed distinct from the Sierra plants. Sacajawea's bitterroot is smaller than its California relatives are, and about half the size of the common bitterroot.

Idahoans can now celebrate both Sacajawea and this unique rare plant named in her honor, 200 years after the Lewis and Clark Expedition!

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