One of the many things I love about late summer are the throngs of colorful, star-shaped flowers that pop up all over the landscape. Most of us are familiar with the yellow ones (sunflowers). But did you know that the same family also produces flowers in purple, red, pink and white? These plants are all part of the Aster family, Asteraceae, the largest and most diverse group in the plant kingdom.
THE ASTER FAMILY STORY
Indeed, the Aster family (also known as Compositae and daisy) is exceedingly large. There are estimated to be over 27,000 known species. They may differ in color, shape and form, but most share two key characteristics. Most asters are composed of two types of flowers, disc and ray.
Gaillardia is a member of the aster family.
Yes, they may look like one flower, but asters are actually composed of many, all fused onto a single flower head. Disc flowers are located in the center and ray flowers are found at the perimeter. The ray flowers are what we commonly refer to as petals.
Zoom in on the photo and you’ll see that the disk is not flat, but domed. And it’s made up of hundreds of tiny flowers!
Leucanthemum (daisy) displaying both tubular and ray florets.
That said, within the family, there are also deviations. Some species consist of only disc flowers while others have only ray.
The flower head of Globe Thistle contains no petal flowers.
Scientists believe that the aster flower head, which also contains seeds and nutrients, helps the plants store energy during periods of drought. It also may contribute to their longevity. In my own experience, I’ve noticed that once established, my Aster family members like coneflower, daisy and blanket flower require very little water. And certainly the many roadside sunflowers, daisies and asters are living proof of these flowers’ remarkable survival ability.
UNEXPECTED FAMILY MEMBERS
Of course every family has its outliers, and the Aster family has a few. These include the food crops lettuce, chicory and globe artichokes. Notice the two types of flowers, both tubular and ray, on the mountain lettuce bloom below.
TAKE THE ASTER FAMILY QUIZ!
Despite all this variation, though, I still find the yellow asters the hardest to identify. At first glance, many of them look alike. But on closer inspection, their flowers are all slightly different.
Below are some well-known Aster family members that bloom in late summer and early fall. Can you identify them? (For answers, please see below.)
Answers: (from top) Coreopsis grandiflora, Golden Marguerite, Rudbeckia (Black-Eyed Susan), Helianthus tuberosis (Jerusalem artichoke), Helenium autumnale (Common Sneezeweed), Helianthus annum (Sunflower), Heliopsis helianthoides (Smooth Oxeye), Gaillardia (Indian Blanket Flower), Arnica montana
GREAT ASTERS FOR GARDENS
Ready to add some of these beautiful flowers to your garden? (or just be able to identify some more members of the family). Following is a list of well-known aster species and their value in the garden.
These popular flowers can be found in gardens all over the world. Popular members include: New England Aster, Echinacea, Rudbeckia, Cosmos, Daisy, Fleabane, Dahlia, Coreopsis, Liatris, Blanket Flower, Fleabane, Zinnia, Chrysanthemum, Oxeye daisy and Yarrow.
HERBAL TEAS, MEDICINE AND FOOD
Aster flowers, leaves and roots have been used for millennia to treat various ailments and diseases. These species include Calendula (Pot marigold), Chamomile, Echinacea, Arnica, Endive, Lettuce and Artemisia.
GREAT NECTOR PRODUCERS
Since they bloom late in the summer and into the fall, asters are a great source of nectar and pollen for pollinators. Some of the best producers are Helianthus annus (Sunflower), Goldenrod, New England Aster and Fleabane.
French marigold, Tagetes patula
Some asters are great at repelling insects. The most well-known among them are marigolds. French marigolds are known to repel whiteflies while Mexican marigolds are said to not only stave off insects but rabbits as well. Other effective ‘insecticidal’ species include Tanacetum, False Fleabane and Chrysanthemum.
Ragweed is a member of the aster family.
Weeds are members, too. Dandelion, Ragwort, Ragweed and Sneezeweed are all part of the Aster family.
Want to know more? For a detailed list of Asteraceae, its genera and where the family fits in the plant kingdom, click here for the USDA Natural Resources Conversation Service.
Looking for garden inspiration? To see photos of my designs, including plant lists, check out my Instagram at carole.herebydesign. I post seasonally from spring through fall.