Buffalobur makes an occasional appearance in King County this time of year. It comes up in late summer when many other plants have already gone to seed or dried up in the heat. Buffalobur’s spiny leaves and flowers harm animals trying to eat it, and it can poison them if animals do succeed in eating it. The burs are also a big problem for wool producers.
The plant’s Latin name is Solanum rostratum and it is in the nightshade family. Its yellow flowers might remind you of other plants in this family, such as peppers and tomatoes, but the rest of the plant is very scruffy, spiny and weedy looking and not likely to confused with other plants in this family. The entire plant, which is about two feet tall and ball-shaped, is covered with sharp, straight, yellow spines.
In our area, look for this plant in gravelly areas, under bird feeders and around farm buildings. Buffalobur is a state noxious weed in Washington and control is required in King County because of its potential impact to livestock and farms. Please let us know where you see this plant so we can make sure it doesn’t spread.
Fortunately buffalobur is not difficult to remove by hand or with a shovel. Just make sure any burs go in the trash to avoid spreading it further. And here’s one tip from personal experience. This plant gets really stinky after it’s been pulled, so don’t store it in your vehicle on a hot day!