The aster is one of the first wildflowers I learned when I first came to Maine, many long years ago. It was pointed out on a natural history hike I went on as part of college orientation. I remembered its name using the mnemonic "ask her"--not very original, but it stuck (I apparently didn't know that "aster" came from the Greek for "star," which would also have been a handy way to remember it). It was even more recently that I realized the great range of different species of aster, and just last summer that I first started trying to puzzle them out. Over the weekend, I attended a naturalists' conference (not to be confused with a naturists' conference), the highlight of which was a field workshop in identifying asters and goldenrods (more on the latter next week). I took my new-found knowledge and applied it to our property, identifying all of the aster species I could find. There were six:
Lance-leaved aster (Symphyotrichum lanceolatum)
Tall White Aster (Doellingeria umbellata)
Heart-leaved aster (Symphyotrichum cordifolium)
Calico aster (Symphyotrichum lateriflorum)
New England Aster (Symphyotrichum novae-angliae)
Awl aster (Symphyotrichum pilosum)
Asters belong to the Asteraceae, or aster, family, sometimes known as composite or sunflower family. You can see their resemblance to sunflowers--with a disk in the center and rays that resemble petals around the outside. Each ray and each little dot inside the disk is actually a whole flower in and of itself, but they all work together to create an inflorescence, or capitula, that looks like a single flower and acts like one in that it attracts pollinators (lots of bees on the asters this time of year). To identify asters, you use many of the same characteristics you use in other flowers--leave shape and attachment; leaf and stem texture; plant, flower (capitula), and leaf size; and color of flowers and stem. Another important identifying characteristic in the asters is the involucral bract--those little green thingies that cradle the base of the flower. Note how they vary among species--some all green and leaf-like, some with a distinct green-and-white pattern, some curling outward, some clinging close.
I know this seems like a lot of fuss to go through to find out who a plant is, but I find it deeply satisfying to put a name to a flower I pass by every day, like making a new friend, and now that I know who these six asters are, I never need peek under their rays at their involucral bracts again; I can look at them and recognize them like old friends, by gestalt. Of course, there's no pressing need to know the names of the flowers, and you can be perfectly happy knowing them simply as "aster" like I did for more than twenty years.
Note that flora refer to asters in the Symphyotrichum genus as "American aster," but I've never heard anyone use this phrasing in real life, so I'm sticking with just plain "aster" here.