This adaptable plant is probably the most common Cerastium sp. (Mouse-Eared Chickweed) in Illinois. Compared to the similar Stellaria spp. (Chickweeds), Mouse-Eared Chickweeds usually have more pubescent leaves and their flowers have 5 styles, rather than 3. Among the many Mouse-Eared Chickweeds that occur in Illinois (most of them are introductions from Eurasia), Common Mouse-Eared Chickweed is the only one with a perennial habit and it is often larger in size. It also blooms later in the year (typically during the summer), while the annual species of Mouse-Eared Chickweed bloom primarily during the spring. A scientific synonym of Common Mouse-Eared Chickweed is Cerastium vulgatum.