Grazing in Michiana
Continuing the series for The Farmer's Exchange, I plan on bringing you a monthly edition of my "Pasture Plant Profiles." I will focus on one less talked-about plant commonly found in pastures in the Great Lakes region and beyond. In this series, I will focus on if that plant is invasive or not, what it adds to the pasture landscape/how livestock utilize it, and some cool and interesting history about the plant I am profiling for the month.
For the month of April, we will be looking at a pasture weed that I have misidentified hundreds of times and still tricks me to this day, American burnweed.
American burnweed is an annual plant that displays alternatively placed leaves on thick, green stems which can range from 1 to 7 feet in height. The leaves are serrated and can be either lobed or unlobed depending on where they are positioned along the stem, generally with the unlobed leaves closer to the root base. The lobed leaves closely resemble wild lettuces, although there is no white latex extruded if squeezed like wild lettuces.
When crushed the smell of the American burnweed has been described as aromatic and spicy. The flower heads are yellow or pink and resemble a closed marigold or other aster flowers, which is the family of plants the American burnweed belongs to.
The flower heads only open minorly and sometimes look like they never open at all, but when the seedhead emerges they again resemble larger dandelions with their cluster of small, wispy achenes their wind dispersed seeds. The plant often branches and grows in a clump with multiple stems.
American burnweed is native to our area of the eastern United States but has become invasive in many other areas of the world including Hawaii, China, Europe and Southern Asia. Most likely this is a result of seeds travelling in other agricultural goods or in the treads of tires, shoes or other equipment.
This is a plant that will not cause any trouble in a pasture; animals will eat it readily. There isn't any toxic risk to it, and it has a completely average nutritional value of 7% fiber and a decent fat content of about 1.7%.
As a weed, it can compete and interfere with certain crops, such as blueberries and strawberries, bringing about economic losses. It can also reduce the aesthetic attributes of the landscape where it's growing.
American burnweed flowers are a pollen source for beneficial insects such as tachinid flies, bees and wasps. However, the plant is also a host for the tarnished plant bug, a piercing-sucking insect that can damage small fruits and vegetables, often causing misshapen fruit and aborted blossoms.
American burnweed might even assist in cleaning up our messes; a Japanese study found that the plant gains high levels of nitrogen by assimilating nitrogen dioxide, which is formed by the burning of fossil fuels.
American burnweed has historically been collected and eaten by foragers and indigenous groups. Many people describe its aroma as pungent as cilantro, but more perfumed, like shiso, with the charisma of epazote and the punch of culantro and lime.