Shirley Heinze Snapshot 8: The Great Marsh, October 3, 2023

Fall Asters

By Dale K. Nichols (Board Member)

Dear friends of Shirley Heinze Land Trust: This is the eighth in a series of “snapshots” featuring our Beverly Shores/Great Marsh preserve.

As we near the end of the growing season, the fall asters are in bloom. Though perhaps not as showy from a distance as many of the plant species showcased in earlier posts, the asters (family name Asteraceae) have their own special beauty and can be found in abundance on SHLT’s Great Marsh properties.

This post will focus on seven different species of asters. All of them are perennials, and the flowers are an important food source for late season pollinators like bees and butterflies. Six are members of the genus Symphyotrichum and the seventh is in the genus Doellingeria. Let’s start with the latter. Doellingeria umbellata, commonly known as the flat-topped white aster or the parasol whitetop, can be seen in abundance along the Great Marsh roadsides. It is typically the tallest of the asters featured here, growing up to 80 inches in height, and it has distinctive flower heads that spread like parasols over the tops of their stems. Each plant can produce as many as 300 small flower heads, each with as many as 16 white ray florets and 50 yellow disc florets.

Doellingeria umbellata

Now on to the marsh’s six Symphyotrichum species. Many of them look quite similar and I, quite frankly, have trouble telling many of them apart. Members of the Stewardship staff could recite differences in leaf structure and the like, but for purposes of this post I will focus on high level details.

The most common of the Symphyotrichum species in the Great Marsh are S. puniceum (commonly known as the bristly, purple-stem or swamp aster), S. firmum (commonly known as the shining aster or smooth swamp aster), and S. praeltum (commonly known as the willow or willowleaf aster).

Typically found in wetland habitats, S. puniceum (bristly aster) grows to a height to 2 to 4 feet, has stems that are often reddish-purple in color, and produces clusters of small, daisy-like flowers with purple to pinkish-purple rays (petals) and yellow centers.

Symphyotrichum puniceum

S. firmum (shining aster) is a close relative of S. puniceum. Its rays range from white to pale blue or lavender in color, and it has yellow to cream-colored disc florets (centers) that turn pink or purple with maturity. Compared to S. puniceum, S. firmum is less hairy overall, has denser inflorescences of smaller, whiter flowers, and tends to grow in larger, denser colonies with long, creeping rhizomes.

Symphyotrichum firmum

The flowers of S. praealtum (willow aster) are similar in appearance to those of S. puniceum and, like S. firmum, willow aster spreads via rhyzomes to form large colonies. One distinguishing characteristic is that each plant of S. praealtum has only a single stem.

Symphyotrichum praealtum

Somewhat less common is S. lanceolatum, commonly known as the panicled aster. It has branching clusters of stalked flowers at the top of the stem, typically with 20 or more flowers per branch. It has small flowers, generally ½ to ¾ inch across with 16 to 50 narrow petals (ray flowers) and a yellow center disk that turns reddish with age. The ray flowers are usually white in color.

Symphyotrichum lanceolatum

The hairy aster (S. pilosum) is found mostly of the road berms and drier edges of the marsh. Similar in appearance to S. lanceolatum, it can be distinguished by its leaf surfaces, which are sparsely to densely covered in long, spreading hairs, with shorter hairs all around the leaf edge (S. lanceolatum leaves by contrast are hairless except around the edges).

Symphyotrichum pilosum

Finally, though not typically a marsh plant, you will see a few New England asters (S. novae-angliae) along the edges of the marsh that perhaps were planted or that might have escaped from cultivation.. Their flowers are easily distinguished from other blue-violet asters by their numerous narrow, purple rays (up to 100) and golden yellow disks.

Hurry out to take a close look at these beautiful fall flowers of the marsh before they’re gone for the season!

Symphyotrichum novae-angliae