Showy Goldenrod

Appearance

Solidago speciosa is a perennial herb up to 200 cm tall, producing a thick underground caudex. One plant can produce as many as 5 stems, each with up to 300 small yellow flower heads.

This perennial plant is usually unbranched and up to 120 cm to 200 cm tall.

The smooth central stem can be green or reddish. The alternate leaves are up to 15.25 cm long and 3.8 cm wide, becoming slightly smaller as they ascend up the stem.

They are narrowly lanceolate or oblong-elliptic, smooth along their margins, and largely devoid of hairs. In the upper half of the plant, there are often small leaves that develop from the upper axils of the primary leaves; they have a wing-like appearance.

The showy inflorescence is up to 2.5 cm long, consisting of an erect panicle of small yellow compound flowers. The flowering stems don't curve outward and downward like many other goldenrods, but are held erect or curve upward.

Each compound flower is about 0.65 cm across, consisting of 4-10 ray florets surrounding the disk florets. The spacing of the ray florets tends to be irregular, and they may not open at the same time.

These flowers occasionally have a mild fragrance. The blooming period occurs during late summer or early fall, and lasts about a month. Later, the achenes develop small tufts of hairs, and are dispersed by the wind. The root system is fibrous and rhizomatous, occasionally forming vegetative offsets. In older mature plants, a woody caudex develops.

Naming

Varieties
'Solidago speciosa' var. 'rigidiuscula' Torr. & A.Gray - mostly in western portions of range
Solidago speciosa var. speciosa - mostly in eastern portions of range

Recently varieties of Solidago speciosa have been separated into species:

Solidago speciosa var. speciosa (now S. speciosa) has basal leaves up to 5 cm wide that persist through flowering and are often coarsely toothed, and mid-stem leaves up to 2.5 cm wide that are not stiff or rough-textured or crowded on the stem;

Solidago speciosa var. rigidiuscula (now S. rigidiuscula) has basal leaves only up to 1.9 cm wide that may not persist to flowering time and are toothless or shallowly toothed, and mid-stem leaves rarely as much as 1.7 cm wide that are stiff, slightly rough-textured, and often crowded on the stem. Note that crowded (or not) may be subjective.

Solidago speciosa var. jejunifolia (now S. jejunifolia) has fewer and narrower leaves, but further details are currently lacking.

Another variety or (subspecies depending on the source) is Solidago speciosa var. pallida. Its leaves are pale green, somewhat glaucous; plants 30–80 cm. Found in easter Colorado, extreme western Oklahoma, and adjacent New Mexico, with disjunct populations in the Black Hills.

Distribution

Much of the eastern US east of the Rocky Mountains and also in Ontario, Canada.

Status

Widespread but var. speciosa is considered rare in Maine (extremely rare, S-rank: S1, threatened), Massachusetts
(rare to uncommon, S-rank: S2S3), New Hampshire (extremely rare, S-rank: S1, endangered), and Vermont
(historical, S-rank: SH).

Habitat

Habitats include mesic to slightly dry black soil prairies, sand prairies, openings in rocky upland forests, Black Oak savannas, thickets, woodland borders, and abandoned fields.

In Michigan: Dry open sandy ground, including oak and jack pine savannas, prairies, fields, rarely dunes, and associated roadsides and railroads; thin soil on high rock mountains in the western Upper Peninsula.

Uses

Often grown in native plant gardens.