With the onset of fall, bright colors in the Arb mean summer’s ending and the preparation for winter. But that is not quite the case for everyone in the Arb: a few late bloomers are still growing. Caught in a downpour last week, the Student Naturalists huddled together to learn about some of the late summer wildflowers of the Arb: asters and false sunflowers. 

Lining the roadside at the edge of the upper Arb, false sunflowers can be hard to identify. When identifying a flowering plant, there are several characteristics that you typically want to look for: a regular versus irregular flower, the number of petals, size, leaf placement, leaf shape, and flower color. The plants we saw were shorter than average—around 2 feet—and had many petals on each large flower. However, they also had toothed leaves with a rough top. Though we knew them to be false sunflowers, Heliopsis helianthoides, they did not perfectly match any species in the key! When you’re trying to identify a plant, keys may not be fully inclusive of the possible range of morphology of a species. 

You can also find many species of aster in the prairie. Asters can be hard to identify at the species level because there are a large number of species with very similar characteristics. The deciding characteristic for the species is the texture of the leaves. There is one species of aster, smooth blue aster (Symphyotrichum laeve), that has a wax coating on its leaves that acts as a protective layer. 

As days turn cooler, head out into the Arb to catch the blues, whites, yellows and oranges of these last fall flowers in full bloom! If you’re interested in identifying plants, a beginner key like Newcomb’s Wildflower guide is useful. You can also download the Seek app by iNaturalist, which can give you a good guess for the species, and learn more about species on the Minnesota Wildflowers website (minnesotawildflowers.info).