Smooth Blue Aster

Symphyotrichum laeve

Smooth Blue Aster (Symphyotrichum laeve) is a native perennial whose light-violet flower heads with yellow centers open from late summer into October, above smooth, waxy, blue-green leaves that wrap around the stem. It grows in open pine woods, meadows and on rocky hillsides, and it is one of the most widely collected asters in the Black Hills.

Free photos from other sources

Smooth Blue Aster: Open cluster of lavender heads with yellow centers — Symphyotrichum laeve. Jason Leduc, CC0 1.0. Get it at the source

Smooth Blue Aster: Plant with many lavender heads beside granite rock — Symphyotrichum laeve. Jane Weeden, CC BY 4.0, resized. Get it at the source

Smooth Blue Aster: Single head with light violet rays and a yellow center, held in fingers — Symphyotrichum laeve. Craig Martin, CC0 1.0. Get it at the source

Smooth Blue Aster: Smooth, narrow leaves whose bases wrap the stem — Symphyotrichum laeve. Jo Roberts, CC BY 4.0, resized. Get it at the source

Smooth Blue Aster: Clump of blue-green leaves before flowering — Symphyotrichum laeve. Cecelia Alexander, CC0 1.0. Get it at the source

Smooth Blue Aster: Fluffy tan seed heads in fall — Symphyotrichum laeve. dghjertaas, CC0 1.0. Get it at the source

Quick facts
Family	Asteraceae · Aster
Status	Native perennial
Blooms	Late July into October, mostly August and September
Height	30–100 cm (12–40 in)
Where	Open pine woods, meadows, rocky hillsides, roadsides and prairie edges
Also called	Smooth Aster, Geyer's Aster, Purple Aster, Glaucous Aster
Synonym	Aster laevis, Aster laevis var. geyeri
Traditional use	Smith (1928) recorded that the Meskwaki burned the plant as a smudge to revive an unconscious person and used it in the sweat bath. Marles and others (2012) record that the Cree chewed the root for toothache and drank a root tea for fever.

Roots, seeds & germination

Root: A short, stout rhizome (underground stem) with a branching crown and fibrous roots. It spreads slowly into loose clumps or small patches and sprouts again from the rhizome after fire.

Seed: A small, flattened, ribbed seed 2–4 mm long, brown to purple, topped with a tuft of tan to reddish bristles that carry it on the wind. Seed ripens from September into late fall, and soil samples have shown no lasting seed bank.

Germination: Easy. Fresh seed needs no pretreatment and began sprouting in about a week in greenhouse trials, while stored seed does better after 30–60 days of cold, moist stratification. SDSU notes the seed needs light, so it is sown on the surface.

How do you identify Smooth Blue Aster?

Check the leaves first: they are hairless, thick, slightly waxy and blue-green, often without teeth, and the upper ones have no stalk and wrap around the stem at the base. The stem is smooth too, often with a bluish or reddish cast. Heads are 1.3–2.5 cm (½–1 in) across, with 13–25 light blue to lavender rays around a yellow center that turns reddish-purple with age, in an open, branching cluster. Aromatic Aster, which blooms at the same time in the same colors, is low and bushy, with small, narrow, rough leaves, sticky hairs and a pleasant smell when crushed.

When does it bloom?

Late July into October, mostly August and September.

Where does it grow?

Open, sunny to lightly shaded ground: ponderosa pine and pine-oak woods, aspen and spruce edges, meadows, rocky and granite slopes, creek banks, roadsides and prairie edges. The 1986 Jewel Cave survey lists it as Aster laevis var. geyeri, and National Park Service lists record it at Wind Cave, Jewel Cave, Mount Rushmore and Devils Tower. About 125 herbarium specimens come from all seven Black Hills counties, including Custer State Park and the Bear Lodge Mountains.