With calls coming in about weed identification, one weed has been particularly popular this year. Burnweed is an erect summer annual plant that can be found throughout the Midwestern and Eastern parts of the United States. Many folks mistake burnweed for horseweed and indeed from the road it does look like horseweed. Burnweeds leaves are slender and oblong, have toothed margins, with indentions generally being different sizes and irregular, and clasp around the stem at the base. The leaves and stems of this plant are bright green and very fleshy. The stems of this plant can have sparse white hairs or they may be hairless. Stems of older plants also have distinguishing vertical indentions. Mature plants can range from 1.5 to 10 feet tall and produce a white feathery seedhead that produces wind-dispersed seeds, similar to that of horseweed. This is why it seems to appear from no where as seed in fields or yards typically blows in from roadsides.

Burnweed is often confused with horseweed. Proper identification is key because burnweed is not difficult to control, and most of our herbicide programs that are in place to control Palmer amaranth will take care of this weed. However, as we all know, horseweed can be more difficult to control and will often require additional herbicides to be utilized. When trying to differentiate horseweed and burnweed, look closely at the stem of the plant. Horseweed plants will have a very hairy stem, where a burnweed plant will have very few to no hairs on the stem. Also, larger burnweed plants will vertical indentions on them stem. Another way to differential these species would to be to look closely at the leaves. Burnweed plants have veins that are indented into the leave and run at approximately a 45^º angle from the midrib of the leave out to the leave margin. The leave of a horseweed have many small veins that protrude out of the leaf.

As far as control pretty much all herbicides used as burndown or broad-spectrum control in crop will do a good job on burnweed.  Which of course is a big difference from horseweed.