What is a common biennial broadleaf weed found in turfgrass settings in Iowa?

Common mallow is a biennial broadleaf weed that frequently appears in turfgrass settings in Iowa. This weed typically has a distinct appearance characterized by its low-growing rosettes of broad, rounded leaves and produces light purple to white flowers. As a biennial, it develops during its first year and then flowers and produces seeds in its second year before dying off.

Dandelion, while a common weed in many lawns, is typically classified as a perennial rather than a biennial. Smooth crabgrass is also a summer annual and not a broadleaf weed at all, as it belongs to the grass family. Ground ivy is a perennial broadleaf weed but does not fit the biennial classification, which is critical for understanding the correct type of weed in the context of the question. Thus, identifying common mallow reinforces an understanding of the characteristics of biennial weeds in turf environments.