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Purple Locoweed Wikimedia Commons
Fabaceae

Purple Locoweed

Oxytropis lambertii

Prairie danger.

Family
Fabaceae
Genus
Oxytropis
Native to
Great Plains, Rocky Mountains
Bloom season
Spring, Summer
Type
perennial herb
Height
0.5-1 ft
Sunlight
full sun
Soil
dry, sandy or rocky, well-drained, prairie or mountain
Water
low
Hardiness
3-8
Lifespan
perennial

Did you know

  • Locoweed contains the alkaloid swainsonine, which interferes with enzyme function in livestock and causes 'locoism' — a neurological syndrome marked by erratic, 'crazy' (loco) behavior.
  • Despite its toxicity to livestock, the plant is beautiful enough to be grown as an ornamental in xeriscape and native prairie gardens far from grazing animals.
  • Selenium hyperaccumulation in locoweed makes it toxic in selenium-rich soils, but the same property makes it a useful indicator plant for selenium deposits.
  • The genus name Oxytropis means 'sharp keel' in Greek, referring to the pointed tip of the boat-shaped keel petal that distinguishes it from true Astragalus milkvetches.
  • Prairie dogs, pronghorn, and various insects feed on locoweed without ill effects, illustrating how toxicity can be highly species-specific.

Color meanings

0

deceptive beauty

1

warning

2

wildness

Uses

  • ornamental (xeriscape)
  • prairie restoration
  • ecological indicator