showy goldenrod

not listed

N5? - Secure

SNR - Unranked

not listed

Showy goldenrod (var.speciosa) is a 8″ to 60″ tall, erect, perennial forb that rises on 1 to 5 stems from a stout, woody caudex in mature plants, from rhizome in young plants. It tends to form clumps.

The stems are erect, leafy, green or reddish, hairless from the base to the inflorescence, and minutely hairy in the inflorescence.

Basal and stem leaves are dark green and are not glaucous. Stem leaves are alternate, smooth to the touch, not crowded, and not firm. Basal and lower stem leaves are broad, inversely lance-shaped or inversely egg-shaped, with the attachment at the narrow end. Basal leaves are 2″ to 12″ long including a short leaf stalk, and 1⅛″ to 2⅛″ wide. The margins are often coarsely toothed. They are usually present at flowering. The upper surface is almost hairless. Middle stem leaves are narrowly egg-shaped to lance-shaped or elliptic, 1″ to 3½″ long, and ¾″ to 1⅛″ wide, becoming smaller as they ascend the stem. They are attached to the stem without a leaf stalk. The margins on the middle leaves are finely toothed, becoming untoothed near the top of the stem. The upper surface is hairless and smooth to the touch. On the upper half of the plant small, wing-like leaves appear in the leaf axils.

The inflorescence is a dense, 4″ to 12″ long, 1″ to 3½″ wide spike with 15 to 300 flower heads. The flowering stems of the inflorescence curve upward rather than out and down.

The flower head has 6 to 8 yellow ray florets and 7 to 9 yellow disk florets.

8″ to 60″

Yellow ray flowers, yellow disk flowers

The 12″, showy flower spike makes showy goldenrod one of the more easily recognized goldenrod species.

Showy goldenrod (Solidago speciosa var. rigidiuscula) has much narrower leaves. Basal leaves are usually absent at flowering. The stem leaves are rough to the touch, crowded, and firm.

Dry to moderate moisture. Open woods, fields, prairies, and plains. Full sun. Sandy or loamy soil.

Late July or early August to early October

Sources

4, 7.

Native

Species Rank
Based on a recent study (Semple et al. 2017), Plants of the World Online (POWO) elevated the varieties and subspecies of Solidago speciosa to species level. It is widely expected that other taxonomic authorities will soon follow suit, but as of this writing (3/21/2021) they have not.

Update
As of 3/11/2024, Catalog of Life, GBIF, NCBI, and World Flora Online have followed Plants of the World Online in elevating the subspecies and varieties of Solidago speciosa to full species rank.