Aster Abundance

September 22, 2024

Author: Phyllis Root
Photographer: Kelly Povo

On the autumn equinox, when summer officially ends and when you can stand an egg on end (I’ve done it), we headed out to Lost Valley Prairie Scientific and Natural Area (SNA). Wind whipped mares’ tail clouds across a blue sky, and swaths of big bluestem  bent in the breeze. 

Most of the prairie flowers had already gone to seed or were well on their way–stiff gentian with seeds like little purple rocket nose cones, prairie blazing star like fuzzy bottle brushes on a stick, skinny whorled milkweed pods pointing skyward.  Several goldenrods still bloomed, including a bright line of showy goldenrod, but the pride of the fall prairie is asters, bright bursts of color busily visited by bees. Lost Valley Prairie lists seven asters out of our state’s twenty-three native asters, and we saw six of the seven including one that wasn’t on the list.  

We’ve been trying to learn to identify the asters, something of a challenge because all of the flowers are either blue-to-bluish-purple or white (except for rayless aster, which has no petals). So what else do we look for besides color?  

Height can help, although plants can range from small to tall.  Still, it’s a start–awl asters can reach five feet tall.  Flower position is also helpful:  awl aster’s white flowers grow only along one side of the stalks, while panicled aster’s similar-looking white flowers grow in bunches at the top of  the stem and in leaf axils (where leaf and stem meet). Heath aster’s tiny  white flowers crowd in tight bunches along the branches.  New England aster’s purplish-pink flowers grow at the top of the stem like a little bouquet. 

Leaves help, too.  Silky aster’s narrow leaves are covered with fine hairs that gives them a soft grey-green look.  Sky-blue aster’s basal leaves are heart shaped, and both basal leaves and stem leaves feel sandpapery on both sides. Aromatic aster’s leaves are said to smell aromatic when crushed, and while we didn’t smell them, we identified the plants by the profusion of leaves that grow smaller up the stem.  

The only one of the listed asters that we didn’t find was smooth blue aster whose petals are (or course) blue and whose leaves are mostly hairless and mostly clasping.  But there’s plenty of fall left for flower chasing, and while we likely we won’t see all of Minnesota’s asters this year, flower by flower we are learning them as we go.

More of what we are seeing now!