North America Native Plant

Salmon River Locoweed

Botanical name: Oxytropis besseyi var. salmonensis

USDA symbol: OXBES

Life cycle: perennial

Habit: forb

Native status: Native to the lower 48 states  

Synonyms: Oxytropis nana Nutt. var. salmonensis (Barneby) Isely (OXNAS)   

Salmon River Locoweed: A Rare Idaho Native Worth Knowing About Meet Salmon River locoweed (Oxytropis besseyi var. salmonensis), one of Idaho’s most specialized native plants. While you probably won’t find this little gem at your local nursery, it’s worth learning about this fascinating member of our native flora – and ...

Rare plant alert!

Region: Conservation status by state

Status: S5T3: Status is uncertain but is somewhere between the following rankings: Subspecies or variety is vulnerable: Either very rare and local throughout its range, found only in a restricted range (even if abundant at some locations), or factors are making it vulnerable to extinction. Typically 21 to 100 occurrences or between 3,000 and 10,000 individuals. ⚘ Secure: At very low or no risk of extinction in the jurisdiction due to a very extensive range, abundant populations or occurrences, with little to no concern from declines or threats. ⚘

Salmon River Locoweed: A Rare Idaho Native Worth Knowing About

Meet Salmon River locoweed (Oxytropis besseyi var. salmonensis), one of Idaho’s most specialized native plants. While you probably won’t find this little gem at your local nursery, it’s worth learning about this fascinating member of our native flora – and understanding why it deserves our respect and protection.

What Makes This Plant Special?

Salmon River locoweed is a perennial forb, which means it’s a non-woody plant that comes back year after year. As part of the legume family, it has the neat ability to fix nitrogen in the soil through a partnership with beneficial bacteria in its roots. This variety is also known by the scientific synonym Oxytropis nana var. salmonensis, reflecting some taxonomic shuffling that botanists love to do!

Where Does It Call Home?

This plant is as Idaho as it gets – it’s found exclusively in the Salmon River region of Idaho, making it a true endemic species. Its extremely limited geographical distribution is part of what makes it so special and, unfortunately, so vulnerable.

Should You Try Growing It?

Here’s where we need to pump the brakes a bit. Salmon River locoweed has a conservation concern that makes it inappropriate for casual home gardening. Its rarity means that any plants you might encounter should be left in their natural habitat to continue their important ecological role.

If you’re absolutely committed to growing this species for conservation purposes, only work with responsibly sourced material from reputable native plant societies or restoration organizations. Never collect from wild populations!

What Would It Be Like in a Garden?

If you could grow it responsibly, Salmon River locoweed would likely thrive in:

  • Alpine or rock gardens with excellent drainage
  • Native plant restoration projects
  • Specialized collections focused on Idaho endemics

Based on its natural habitat, it would probably prefer well-drained, rocky soils and could handle Idaho’s challenging mountain conditions. As a legume, it would also contribute to soil health by fixing nitrogen.

Better Alternatives for Your Garden

Instead of seeking out this rare variety, consider these more readily available native Idaho legumes that can give you similar ecological benefits:

  • Other Oxytropis species that are more common
  • Native lupines (Lupinus species)
  • Native vetches (Vicia species)
  • Milk vetches (Astragalus species)

Supporting Conservation

The best way to grow Salmon River locoweed is to support habitat conservation in Idaho’s Salmon River region. Consider donating to or volunteering with local conservation organizations working to protect Idaho’s unique plant communities.

Sometimes the most beautiful way to appreciate a rare plant is to leave it wild and work to keep its habitat intact for future generations to discover and admire.

Salmon River Locoweed

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Rosidae

Order

Fabales

Family

Fabaceae Lindl. - Pea family

Genus

Oxytropis DC. - locoweed

Species

Oxytropis besseyi (Rydb.) Blank. - Bessey's locoweed

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA