Death Camas in Glacier County

Kari Lewis, MSU Extension - Glacier County

The death camas plant is a
perennial bulbous native
forb in the lily family. 
Photo by Kari Lewis.

This morning I had a sample of the death camas plant come into the office, and our range specialist, Dr. Jeff Mosley has confirmed that this is, “another big year’ for death camas across Montana.  Death camas is a toxic rangeland plant that resembles wild onion (and can cause severe illness in humans if mistaken for wild onion).  In my producer’s case, they have lost two healthy calves presumably to the death camas, so I wanted to take some time to alert producers to plant.

Death camas is a perennial bulbous native forb in the lily family.  Plants have linear grass-like leaves and the flowers are in panicles with creamy white petals.  It does somewhat resemble a shorter version of Beargrass, which you commonly spot in Glacier National Park. 

Death camas is highly toxic to cattle, sheep and horses.  The entire plant is toxic, but especially the bulb of the plant.  When soil is moist, such as after a rain like we’ve had, the bulb is much easier for livestock to pull out of the ground and ingest.  Sub-lethal doses of death camas can also decrease animal weight gain, milk production, and inhibit reproduction. 

The death camas bulb resembles wild onion.  Photo by Kari Lewis.

Death camas greens up early in the season so it is more palatable than other plants.  As the death camas matures, it will become less palatable and hopefully livestock will instead prefer grass. 

The death camas flowers are in panicles
with creamy white petals. 
Photo by Kari Lewis.

So, why are we seeing death camas this year?  Following a drought year, there is less carryover grass from the previous growing season so there may be less other forage available to buffer a toxic plant.  In addition, some research suggests that death camas is more toxic to livestock during cool, stormy weather, such as we’ve had these past few days.  As the barometer drops, the chemical structure of the toxins in death camas actually becomes more toxic which increases the chances of livestock poisoning as they have to eat even less of it to consume a lethal dose. 

If you do have death camas in your pastures, there are a few recommendations:

• Delay turn-out to those pastures to allow the death camas plant to mature and to allow the grass to grow more.  Toxicity is most common if grass is in short supply or there is little residual grass from the previous year.
• Graze death camas pastures lightly.  If livestock are short on available forage, they are more likely to consume plants such as death camas.  You may consider grazing those pastures very lightly, and then coming back to them later in the season after the death camas has matured and is less palatable.
• In terms of chemical control, 2,4-D can be used early in the growing season before the flowering stalk appears.  Likely we are past that control window now, but producers could flag or GPS spots where death camas are so that control can be applied next spring. 

If you have plants you believe to be death camas, you can bring them into your local MSU Extension Office for confirmation.

Additional Resources regarding death camas:

MSU Ag Alert from Dr. Jeff Mosley

Great Falls Tribune article from 2016

NRCS Plant Guide