Late Goldenrod is a native erect perennial and is a common roadside Goldenrod.
Stems: It grows from 1 to 5 feet high. The stem usually has short hair throughout but the base of the stem may sometimes lack hair.
Leaves are alternate, narrow and lance shaped with sharp teeth, larger leaves with two noticeable veins parallel to the mid-rib. Upper stem leaves will be without teeth. Most leaves are sessile (stalkless) but base leaves may have a short stalk and these usually wither by flowering time. The underside of the leaf has hair on the main veins and nerves and both the underside and the upper-side are somewhat rough from fine stiff hairs. These hairs give the leaves a gray/green tone.
The floral array is a spreading pyramidal cluster at the top of the stem with the flowers on one side of each branch of the cluster, which branch tends to recurve backward (downward).
Flowers: The yellow flower heads are less than 1/4 inch across, composed of two types of florets: 5 to 13 tiny pointed ray florets, with yellow rays, which are pistillate and fertile, and 3 to 6 disc florets with yellow corollas whose lips are pointed and erect to spreading during pollination. These are bisexual and fertile. The disc florets have 5 stamens with yellow filaments and anthers. These surround and are appressed to the style. Anthers turn darker at pollen maturity. The thin phyllaries are yellowish to yellow-green in color and these surround the flower head in 3 series of unequal size. The outer series lanceolate in shape with pointed tips and the inner series more linear with tips less pointed.
Seeds are dry cypselae, 0.5–1.5 mm, with a fluffy whitish pappus for wind dispersal. The cypselae are tan and are of a shape called narrowly 'obconic' - that is like a narrow inverted cone. Seeds of Solidago usually require 60 days of cold statification and light for germination.
Habitat: Late Goldenrod is subject to some interesting galls (see below). The plant can form dense colonies from its creeping rhizomes and of all the goldenrods, this one could be considered invasive as it spreads readily by the roots and by seed. It grows in roadsides, open fields, prairies where there is full to partial sun, moist to dry conditions.
Names and varieties: The genus Solidago is from the Latin solido, to 'make whole' as the plants of this genus were known to "make whole". (see bottom of page). The species altissima means 'tallest'. This species is one of the tallest native goldenrods. The author name for the plant classification - 'L.' refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy.
An attempt to explain the names: The common names in the list above are sometimes interchanged. S. altissima should be referred to as Late Goldenrod and S. canadensis as Canada Goldenrod. USDA lists both S. canadensis and S. altissima as 'Canada Goldenrod'. Our Minnesota sources, the DNR and the U of M Herbarium, both list S. altissima as Late Goldenrod as does the authoritative Flora of North America whose classification I follow here. S. altissima is sometimes treated as S. canadensis var. scabra but that variety does not show the gray/green leaves. The insect galls (see below) rarely appear on S. canadensis. The differences between S. canadensis and S. altissima require close inspection of the florets and leaves. See bottom of page for more location specifics and subspecies specifics.
Above: The 1/4 inch wide flowers have both ray and disc florets. 2nd photo and below - The phyllaries are linear and light yellow to greenish-yellow in color. 3rd photo - The leaves have 3 prominent veins.
Below: 1st photo - The stem has fine short hairs top to (usually) bottom. Stems may show some red coloration. 2nd photo - Leaf detail. Upper and lower leaves (center photo) vary greatly in size. The larger leaves have sharp teeth. 3rd photo - The underside has fine hair on the veins and nerves.
Below: 1st photo - The flower branches of the inflorescence have flowers on one side only and tend to curve backwards. 2nd photo - The seed is a small dry cypsela with a fluffy white pappus attached to carry them in the wind.
Below: The floral array in seed has a beauty of its own.
Below: The root system with its long spreading rhizomes - very aggressive spreading plant.
Goldenrod Galls: Late Goldenrod (Solidago altissima with two subspecies) is subject to three different types of stem galls caused by tiny insects that lay their eggs on the plants The larva from the hatched egg then eats its way into the stem. In two cases (ball gall and spindle gall) the plant then responds to this event by rapidly increasing cell growth around the intrusion, enveloping the larva in a woody protective sheathing that not only keeps the larva safe, but they have a ready-made food supply for the remainder of the summer and a home to overwinter in and emerge in spring as a new adult, unless a woodpecker finds them. In the case of the rosette gall (3rd photo below), the plant creates a dense growth of what looks like small leaves at the top of the plant after a larva hatches at the top of the stem. This rosette is caused by the plant stopping stem growth without stopping leaf production. In the case of the spindle gall (below- 2nd photo), the eggs are laid on an autumn leaf where they overwinter. In spring the hatched larva migrate from the dead leaf to a nearby stem, bore in for a home and the plant responds as indicated above. S. canadensis (two subspecies) is not known to be seriously affected by the galls.
Below: 1st photo - The "ball" or "apple" gall. 2nd photo - The "spindle" gall. 3rd photo - The "rosette" gall.
The insects that cause these galls are as follows: Ball gall - Goldenrod Gall Fly, Eurosta solidaginis; Spindle Gall - Goldenrod Gall Moth, Gnorimoschema gallaesolidaginis; Rosette Gall - Goldenrod Gall Midge, Rhopalomyia solidaginis. This gall only occurs on Late Goldenrod. Below: 1st photo - A larva of the Gall fly in the sectioned gall. Note the gall has a dense woody structure. 2nd photo - An example of a stem affected by all of them.
Notes: Late Goldenrod is indigenous to the Garden area. Eloise Butler catalogued it on Sept. 6, 1907 as S. canadensis, but as explained above, that species is not found in Hennepin County where the Garden is located. Instead it had to be S. altissima and in fact, on Sept. 6, 1917 she recorded seeing S. altissima in the Garden. It was listed on Martha Crone's 1951 inventory of plants in the Garden at that time as Tall Goldenrod, and listed on subsequent Garden plant census'. This is one of the most wide spread goldenrods, the two main species, S. canadensis and S. altissima, occurring in most of Canada and all states of the U.S. except the very SE corner.
Subspecies: There are 18 species of Solidago known in the wild in Minnesota. S. altissima has two subspecies in Minnesota - subsp. altissima and subsp. gilvocanescens. They differ in the size of the flower. Both are subject to insect galls and both are found in the metro area including Hennepin County. The two subspecies of S. altissima have range overlap with subsp. gilvocanescens belonging more to the Great Plains east to Illinois and subsp. altissima also being on the east edge of the Great Plains and then eastward through the U.S. and Canada. S. canadensis has two varieties in Minnesota - var. canadensis and var. hargeri. These two are far less common in Minnesota, found in only a quarter of the counties, not subject to insect galls and are not known in the metro area at all per the MN-DNR surveys.
Medicinal Lore: The genus Solidago has several species including, altissima and canadensis, whose leaves and tops were used by natives for sickness of the stomach - usually a teaspoon of leaves to a cupful of boiling water. Hutchins (Ref. #12) mentions several other uses. Here in Minnesota, Frances Densmore (Ref.#5) reported that the Minnesota Chippewa used various species of Goldenrod, including S. altissima, for treating cramps, fevers, colds, ulcers and boils. As regards S. canadensis specifically, the root and flowers were used. Moistened pulverized root was applied as a poultice for boils; similarly, moistened dried flowers were applied to skin ulcers and those same flowers when mixed with flowers of giant hyssop and green-headed coneflower. became a poultice for burns. Mrs. Grieve (Ref. #7) reports on European use of various species.
References: Plant characteristics are generally from sources 1A, 32, W2, W3, W7 & W8 plus others as specifically applied. Distribution principally from W1, W2 and 28C. Planting history generally from 1, 4 & 4a. Other sources by specific reference. See Reference List for details.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"