For the second year in a row, I’m ending Bleeding Heartland’s wildflower series with pictures of asters. They are often the last wildflowers you see’ll in the fall, as some species continue to bloom even after several frosts, when most other plants have turned brown. The pictures after the jump were taken in late September, but within the past few days I’ve seen some white asters still in flower.

Iowa wildflower Wednesday will resume in the spring, whenever I manage to take some pictures of early bloomers such as skunk cabbage, trillium, or pasque flower.

This is an open thread: all topics welcome.

I asked some native plants experts for help in identifying these white asters. To my eye, they most closely resembled either frost aster (Symphyotrichum pilosum) or white heath aster (Symphyotrichum ericoides). I learned that identifying plants in this group is difficult even for experts. Since I found these flowers near a pond, and frost asters tend to thrive in wet soils (unlike white heath asters), I was advised to settle for “Symphiotrichum cf. pilosum,” with the “cf.” indicating “most likely” or “after the form of.” Frost aster is common throughout the midwest.  

Your guess is as good as mine on the ID of these purple asters, also found near a pond in late September. I saw similar flowers blooming even at the end of October.

Some of the late-blooming asters appear more pink than purple.