Two people stand on a grassy hillside in the King Range Wilderness, overlooking the Pacific Ocean.
California Poppies Headwaters Forest Reserve Kayaker enjoying the California Coastal National Monument Headwaters Forest Reserve King Range National Conservation Area
BLM>California>Arcata>Noxious Weeds>Noxious Weeds Program
Print Page
Arcata Field Office

Gopher Weed or Caper Spurge (Euphorbia lathyris)

Spurge Family (Euphorbiaceae)
Gopher Weed
Description: Gopher weed is an erect biennial (occasionally annual) plant growing up to 5 feet tall, with a blue-green stem and leaves. The waxy leaves are arranged in opposite pairs, and are about 6 inches long and one inch wide. The flowers are green to yellow-green, less than 1/4 inch, with no petals. The seeds are green ripening brown or grey, produced in globular clusters of three seeds compressed together.
All parts of the plant, including the seeds and roots are poisonous. Handling may cause skin irritation as the plant produces latex. While poisonous to humans and most livestock, goats sometimes eat it and are immune to the toxin. However, the toxin can be passed through the goat's milk.
Habitat: Gopher weed grows in well drained, dry or moist soils, with partial shade to full sun in a wide variety of habitats.  
Distribution: Gopher weed is a native of southern Europe, northwest Africa, southwest Asia and western China.  Away from its native range it is invasive and is naturalized in many regions.   This plant reproduces with repeated blooming, and spreads from seed delivered to the ground by exploding seed pods.
Flowering Period: May through June; seeds ripen July through August.