Beware of buffalobur

Buffalobur is in the Solanaceae or Nightshade family. Like many of the noxious weeds on our list, buffalobur grows bright yellow flowers. These flowers may be bright yellow and inviting until you get close enough to realize that the entire plant except for the flowers is covered in sharp spines.

The stout spines of buffalobur are not merely sharp, they are also covered with a substance that can cause intense lingering pain if stabbed by them. When mature, the stem can break off and the plant becomes a tumbleweed which spreads the astonishingly high number of seeds, up to 8,500 per plant.

The most dangerous characteristic of buffalobur is that it is poisonous. Buffalobur can poison horses, sheep, goats and cattle. However, sheep and goats are more resistant than cattle.

In controlled experiments, goats were not poisoned at all. Buffalobur like other poisonous nightshades (Solanum spp.) contains the deadly glycoalkaloid solanine and the tropane alkaloids. In some instances, as little as 0.1 to 0.3 percent of an animal’s weight in buffalobur is enough to be toxic. It is also capable of accumulating excess nitrates in soils high in nitrogen, so it can cause nitrate and solanine poisoning.

Unlike many of the noxious weeds on our list, buffalobur is a native to the Midwest region of the US and native to Mexico. It is also on the Washington state quarantine list. This makes it illegal to buy, sell or offer it for sale in the state of Washington.

This weed can be found in many places, including overgrazed pasture, roadsides, yards and waste areas. It can grow in almost any type of soil. Because it is a common birdseed contaminant, it can often be found in yards around birdfeeders.

Because buffalobur is an annual, it only reproduces by seeds and does not spread via an underground rhizome root system. Because it is an annual, mechanical removal methods such as digging or tilling can be effective. If pulling, consider wearing gloves. If you can wet the soil first, it will make pulling them out easier.

Since buffalobur can outcompete native forage and is toxic to livestock, it can be an aggressive pasture and rangeland weed. It is recommended that you take immediate action to control this weed as soon as you find it. It is always easier to control noxious weeds before they get out of control.

If you need help identifying this or any other weed on your property, please give our office a call at (509) 754-2011, ext. 4710, or visit our website at www.grantcountyweedboard.org.