Oblong-Leaved Aster (Aromatic Aster)

Photo of oblong-leaved aster showing masses of purple flowerheads
Scientific Name
Symphyotrichum oblongifolium (formerly Aster oblongifolius)
Family
Asteraceae (daisies)
Description

Oblong-leaved aster, or aromatic aster, is a much-branched perennial with fragrant foliage. Flowerheads terminal, few to many heads, with 20–40 ray florets that are blue or purple (rarely rose pink); disk florets yellow. Blooms July–November. Leaves alternate, sessile, narrow, clasping the stem, with or without small “ears” at the base, oblong to lance-shaped, lacking teeth, from 1–3½ inches long.

Similar species: There are 24 species of Symphyotrichum in Missouri, plus many hybrids and varieties. This species is notable for the fragrance of its foliage and its crowded, stalkless, clasping, hairy, narrow (oblong) leaves. For more information about our native New World asters, see their group page.

Size

Height: to 3 feet.

Where To Find
image of Oblong-Leaved Aster Aromatic Aster distribution map

Scattered mostly south of Missouri River except Southeast Lowlands, scattered in northern Missouri, especially in eastern counties. Cultivated statewide.

Occurs in glades, ledges and tops of bluffs, upland prairies, openings of dry upland forests and along railroads. As with several other of our native asters, this species can hybridize with its close relatives where they grow in the same vicinity. Special cultivars and hybrids are often available at garden centers.

For many years, nearly all native North American asters were considered members of the genus Aster, formerly a very large genus that is now considered to comprise Old World species almost exclusively. Molecular (DNA) studies have shown that the former genus had included several groups that deserve to be treated as separate genera. The only "true aster" (in the genus Aster) that grows wild in Missouri is a native of Eurasia that escapes from gardens.

In cultivation, this native aster does well in rock gardens, where it develops a pleasant shrubby habit when grown in full sun. Other asters can become more lanky. Like most of our native asters, it blooms late in the season and contributes to the beauty of Missouri's fall landscape.

Many types of bees, butterflies, and skippers visit the flowers. Moth caterpillars and various other insects eat the leaves. Deer and some other mammals eat the foliage, and wild turkey eat the seeds.

Media Gallery
Photo of oblong-leaved aster showing masses of purple flowerheads
Oblong-leaved, or aromatic aster, is well-named. It is notable for its fragrant foliage and its crowded, stalkless, clasping, hairy, narrow, oblong leaves.
Jim Rathert
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Aromatic aster flowerhead and foliage
Oblong-leaved aster, or aromatic aster, is a much-branched perennial with fragrant foliage.
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Side view of aromatic aster flowerhead, showing recurving involucral bracts beneath the purplish ray flowers
As with most members of the daisy, sunflower, and aster family, the green, overlapping bracts beneath the flowerhead are very helpful for identifying aromatic aster.
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Opening flowerhead of aromatic aster
Like most other New World asters, the ray flowers of aromatic aster may show a variety of reddish to bluish purple or pink colors. Also, the color of each flowerhead typically changes as it opens, matures, and ages.
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Leaves and stems of aromatic aster plant
Leaf shape, texture, and hairiness are important identifiers for New World aster species. Aromatic aster has small round glands on its fragrant, hairy leaves, which clasp the stem and lack teeth.
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Purple flower
Noppadol Paothong
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Photo of oblong-leaved aster showing masses of purple flowerheads
Aromatic aster flowerhead and foliage
Side view of aromatic aster flowerhead, showing recurving involucral bracts beneath the purplish ray flowers
Opening flowerhead of aromatic aster
Leaves and stems of aromatic aster plant
Purple flower
Similar Species
About Wildflowers, Grasses and Other Nonwoody Plants in Missouri
A very simple way of thinking about the green world is to divide the vascular plants into two groups: woody and nonwoody (or herbaceous). But this is an artificial division; many plant families include some species that are woody and some that are not. The diversity of nonwoody vascular plants is staggering! Think of all the ferns, grasses, sedges, lilies, peas, sunflowers, nightshades, milkweeds, mustards, mints, and mallows — weeds and wildflowers — and many more!