Native Poisonous Plants

Here is are the most poisonous native plants in La Plata County.  Each species has a link for pictures and detailed information from Colorado State University. 

death camas

Death camas (Zigadenus venenosus)

Zigadenus venenosus, commonly called death camas or meadow death camas, is a flowering plant in the genus Zigadenus belonging to the Melanthiaceae. It grows up to 70 cm tall with long, basal, grass-like leaves.

The bulbs are oval and look like onions but do not smell like onions.

The flowers are cream coloured or white and grow in pointed clusters,flowering between April and July.

More Pictures (click here)

CSU Data Sheet

Lupine-Lupinus prunophilus

A common native plant in higher elevation landscapes. Each leaf has 6-9 narrow leaflets. The flowers are white to blue/purple, pea-like, produced at the end of branches. Seeds are produced in pea-like pods.Sheep are most susceptible to the toxic properties, but cattle, and horses also susceptible. Goats are quite resistant to the toxic effects of lupines.

More Pictures (click here)

CSU Data Sheet


Larkspur

Delphinium nuttallianum

Larkspur is a native that grows at higher elevations. Fatal poisoning occurs mainly in cattle. When using herbicides on this and other poisonous species, care should be taken to keep grazing animals off infested areas until treated plants have totally expired. Herbicides increase sugar production in treated weeds making them more palatable.

CSU Data Sheet

Purple Locoweed

Oxytropis sericea

Flowers vary in color by species, with silky crazyweed having white flowers and Lambert crazyweed having purplish-pink flowers. All livestock species can be poisoned by eating crazyweed. Horses never recover once they are poisoned. Abortions in cattle and sheep are common from eating these plants.

More Pictures (click here)

CSU Data Sheet

Twogrooved milkvetch

Astragalus bisulcatus

Members of this genus are poisonous, affecting cattle, sheep and horses. Two grooved milk vetch contains both selenium and swains onine,the alkaloid responsible for locoism. As little as 2 lbs. can cause acute poisoning in mature cows within a few hours after being eaten. Poisoning symptoms are respiratory problems and paralysis of the hind legs.

CSU Data Sheet

 

Western Waterhemlock

Cicuta douglasii

Highly poisonous perennial that is found in wet areas and sometimes growing among cattails or along irrigation canals. One bite is fatal to humans and animals. Rubber gloves are recommended when handling this plant. Leaf veins that terminate at the bottom of leaf serrations identify this plant. It is often fatally mistaken for water parsnip or other edible members of this family. Numerous deaths are attributed to this species. After ingesting, violent death normally occurs within a half hour.

More Pictures (click here)

CSU Data Sheet

Western Whorled Milkweed

Asclepias subverticillata

 

White flowers and milky latex sap identify this perennial species. Reproduces by seeds and horizontal underground roots.

More Pictures (click here)

CSU Data Sheet

White Locoweed

Oxytropis sericea

Flowers vary in color by species, with silky crazyweed having white flowers and Lambert crazyweed having purplish-pink flowers. All livestock species can be poisoned by eating crazyweed. Horses never recover once they are poisoned. Abortions in cattle and sheep are common from eating these plants.
More Pictures (click here)

CSU Data Sheet