Rare Idaho Plants at the IBG

Did you know that IBG has three globally rare species in our plant collection? Two of the plants came to us because their populations were going to be destroyed and the “rescued” bulbs and rhizomes needed a new home. Aase’s onion (Allium aaseae) bulbs were planted in 2006 after being salvaged from county lands slated for landfill expansion. The entire range of this species is in southwest Idaho, where it grows on deep sandy soils in about 4 counties. Flowering is in March and April. You can see it in the Lewis and Clark Native Plant Garden.


McFarlane’s four o’clock (Mirabilis macfarlanei) occurs in Hell’s Canyon and a few small populations along the Salmon River, but its entire global range is within 3 counties. This stunning beauty is extremely deep rooted and long-lived. Rhizomes were salvaged and planted IBG at several different occasions over the last 20 years. McFarlane’s four o’clock flowers in the Western Waterwise Garden in May and June.

The third species, Sacajawea’s bitterroot (Lewisia sacajaweana), came to us through our participation in the Boise National Forest’s “Imperiled Plant Species Genetic Conservation” program. Small collections of Sacajawea’s bitterroot are being grown in trough-type containers to attempt to gather seed for long-term seed banking purposes. This species, which comes and goes quickly, is found on granitic soils at 6000-8000 feet elevation, and only in Idaho.

You can learn more about all three species at Idaho Fish and Game

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