Greasewood (
Sarcobatus vermiculatus) is erect, spiny, woody perennial shrub that is found growing in the western United States. It starts growing in early spring with leaves remaining until the first freeze. The plant is moderately palatable to livestock, and therefore can be a problem if found growing in horse pastures.
Greasewood Toxic Components
S. vermiculatus contains soluble sodium and potassium oxalates. Oxalate levels in
S. vermiculatus vary depending on season, stage of growth and environmental factors. If large quantities of
S. vermiculatus are ingested over a short period of time it can cause kidney damage due to high levels of oxalates. Signs develop within 4 to 6 hours after ingestion of the plant.
S. vermiculatus is also a
contact dermatitis causing plant. The leaves contain higher concentrations of toxins than other parts of the plant. The levels of the toxin in plants varies considerably in the different areas where it grows (from 10-22% of plant dry weight). Greasewood poisoning appears similar to that caused by the halogeton plant--resulting in
hypocalcemia, renal necrosis and subsequent uremia. No treatments have definitively proven to be effective for greasewood poisoning.
What Greasewood Looks Like
Greasewood grows to a height of 1 to 1.5 meters. It has multiple low, spreading branches that are brittle and spinescent; the ends of smaller branches taper to sharp thorns. Leaves are ½ to 2 inches long, bright green, strap-shaped and somewhat fleshy. It has greenish small and inconspicuous flowers and cone-shaped fruiting spikes about ½ inch long. The bark is smooth and white.