General: Fivehorn Smotherweed (Bassia hyssopifolia) is an invasive shrubby annual. The plant grows upright with inconspicuous flowers, and the linear leaves are gray-green and covered with short hairs. The flowers lack petals, but the sepals are radial and 5-lobed. The lobes are covered with soft, furry, tan hairs, and each lobe has a hook on the back.

Fivehorn Smotherweed is a nasty, invasive weed that is an uncommon component of disturbed semi-desert vegetation. Around Las Vegas, this species is uncommon -- let's all work to make sure it stays that way.

Keep an eye out for this species. Land managers are actively working to eradicate Fivehorn Smotherweed, so hopefully you won't see it anywhere. Fivehorn Smotherweed is on the "Watch Weeds" list in the Lower Las Vegas Wash.

Family: Goosefoot (Chenopodiaceae).

Other Names: fivehook bassia, smother weed, Echinopsilon hyssopifolius, Kochia hyssopifolia.

Plant Form: Shrubby annual.

Height: To about 4 feet.

Stems: Many.

Leaves: Gray-green, short, narrow, lanceolate.

Flowers: Inconspicuous. Flowers grow along the flower stalks; petals none; sepals radial, 5-lobed, lobes covered with soft, furry, tan hairs, each lobe has a hook on the back.

Seeds: Small, flat, remain enclosed in sepals.

Habitat: Wetlands, roadsides, disturbed sites, pastures.

Elevation: To about 4,000 feet.

Distribution: Western U.S., western Canada, and a few central and eastern states. Native to Eurasia.

Comments: This invasive weed can be toxic to livestock.

For More Information: DiTomaso, J.M., and E.A. Healy. 2007. Weeds of California and other Western States. University of California Agricultural and Natural Resources Publication 3488. 2 Vol. ISBN 978-1-879906-69-3.