Solidago canadensis var. salebrosa

Native

Moist to dry. Prairies, fields, ditches, roadsides, and forest openings. Full to partial sun.

August to October

Yellow ray florets, yellow disk florets

10″ to 60″

This is a 10″ to 60″ tall, erect to ascending, perennial forb that rises on 1 to 20 or more stems from long, creeping rhizomes. It often forms large, dense patches. The roots and leaves exude toxic chemicals that inhibit the growth and survival of competing species (allelopathy).

The stem is erect and leafy. It is not shiny and not covered with a whitish, waxy bloom (glaucous). The lower half of the stem is hairless or sparsely hairy. The upper half is densely covered with short hairs.

There are no basal leaves. Stem leaves are alternate, narrowly or broadly inversely lance-shaped, and thin. Lower to middle stem leaves are 1⅜″ to 4″ long, though usually less than 3″ long, and ¼″ to ¾″ wide, though usually no more than 9 ⁄16″ wide. The lowest leaves are must smaller. The leaf blade is distinctly 3-veined, but this may not be obvious. It tapers to the base and is attached to the stem without a leaf stalk. It tapers to a point at the tip with straight sides along the tip. The upper surface is hairless. The lower surface is almost hairless or sparsely short-hairy. The margins are toothed with 0 to 9 sharp, forward-pointing teeth per side, and have a fringe of hairs. Lower to middle stem leaves are usually withered by the time the plant is in flower. Middle to upper stem leaves are similar, inversely lance-shaped in the middle of the stem, becoming lance-shaped toward the top of the stem. They are ¾″ to 2⅜″ long and ⅛″ to 7 ⁄16″, though usually no more than 5 ⁄16″ wide, largest near the middle of the stem, becoming somewhat smaller as they ascend the stem. The upper surface is hairless. The lower surface is hairless or sparsely hairy, especially along the main veins. The margins are usually untoothed or minutely toothed, rarely toothed with 1 to 8 sharp, forward-pointing teeth per side.

The inflorescence is a narrowly pyramidal or club-shaped, congested, many-branched, 4″ to 8″ long, 1½″ to 3″ wide cluster with 12 to 500 or more flower heads. The flowering branches are ascending or sometimes arching. The flower heads are arranged on one side of the branch.

The tiny flower heads are less than ¼″ wide. They have 8 to 17, usually 11 to 15, yellow ray florets and 3 to 16, usually 5 to 11, yellow disk florets. The whorl of bracts surrounding the base of the flower head (involucre) is 1 ⁄16″ to ⅛″ long and yellowish in color. The corolla is 1 ⁄16″ to ⅛″ long.

Canada goldenrod (Solidago canadensis var. canadensis) flower heads have only 3 to 6 disk florets.

Early goldenrod (Solidago juncea) stems are hairless.

Giant goldenrod (Solidago gigantea) stems are hairless and sometimes covered with a whitish, waxy bloom.

Harger’s goldenrod (Solidago canadensis var. hargeri) stem is moderately hairy both above and below the middle, though it may be hairless or nearly hairless very the base. The flower heads tend to have fewer ray florets, usually 5 to 10, averaging 9, and have fewer disk florets, 2 to 4. It has been recorded only in Grant County in western Minnesota.

Tall goldenrod (Solidago canadensis var. scabra) is moderately to densely hairy both above and below the middle. There are often large insect galls on the lower and middle part of the stem. Fresh plants often have a gray-green tone from the short hairs on the leaf surfaces. The plant is usually hairy throughout. The leaves are relatively thick and firm. The involucre is longer, ⅛″ to 3 ⁄16″ long. The flower heads tend have fewer disk florets, usually 3 to 6.

No information available

A study in 2002 showed that Canada goldenrod inhibits the growth and survival of competing species by exuding toxic chemicals from its roots and leaves.