Tall Goldenrod (Solidago gigantea) — identification, habitat & look-alikes

Tall goldenrod, also called giant goldenrod, is a native perennial that grows wild across most of North America east of the Rockies, and in late summer and fall a single plant can carry a great many tiny yellow flower heads. It is the easiest to identify of the Canada goldenrod group: its stem is smooth and hairless, often reddish and sometimes covered with a whitish waxy coating.

Appearance

Appearance: Usually 2–6 ft (0.6–1.8 m) tall. Stems are stiff and smooth below the flower clusters, often reddish and sometimes covered with a whitish bloom.
Growth form: Spreads by creeping underground stems () and often forms colonies.
Leaves: No basal leaves. Stem leaves are lance-shaped, about 2.5–6.5 in (6–17 cm) long, with three prominent veins and sharp teeth. The undersides are hairless or slightly hairy on the veins. Lower leaves often wither by bloom time.
Flowers: Tiny yellow heads about ¼ in (6 mm) across, lined up on one side of arching branches to form a big pyramid-shaped cluster.
Flowering time: Late summer into fall; August through October in Minnesota.
Fruit: Small brown seeds with a tuft of whitish hairs that carries them on the wind.

Look-alikes

Canada goldenrodSolidago canadensis

Canada goldenrod has hairy stems and usually hairier leaves. Tall goldenrod's stem is smooth, often reddish and sometimes covered with a whitish waxy coating.

Why they get mixed upBoth are tall, colony-forming goldenrods with big arching flower clusters.

late goldenrodSolidago altissima

This species also has hairy stems and hairier leaves. Run a finger down the stem below the flowers: smooth means tall goldenrod.

Why they get mixed upFrom a distance its tall plumes of yellow flowers look much the same.

Missouri goldenrodSolidago missouriensis

It also has a hairless stem but is much shorter, usually under 3 ft (1 m), with stalked lower leaves that get noticeably smaller up the stem.

Why they get mixed upBoth have smooth stems.

Where it lives

Typical habitats: Meadows
Old fields
Stream and river banks
Marshes
Woodland edges
Roadsides
Range: Native across most of North America east of the Rocky Mountains, and into northeastern Mexico.
Preferred conditions: Full sun and soil that is moist at least part of the year.
Flowering: Flowers Aug–Oct
Flowers Aug–Oct

Conservation

IUCN Red List: NENot EvaluatedNot yet assessed
Threats: Outside its native range it is a serious invader in Europe and Asia, where dense stands reduce native plant diversity.

Culture and stories

Culture and stories: Goldenrod is the state flower of Nebraska (adopted 1895) and Kentucky (1926), and both are listed as this species. Nebraska's original law used an older name for it, Solidago serotina.