Grass-leaved Goldenrod is an erect native perennial forb, growing from 1 to 4 feet high on stems that are usually smooth and hairless but very leafy. There may be some dense stem hair in the upper stem section. Branching occurs near the top 10 to 25% of the stem providing open space between the flower clusters.
The leaves are alternate, spreading to ascending, linear to lanceolate in shape, without teeth but margins may have some short stiff hair and larger leaves may show some sparse hair on the mid-vein. There are 3 to 5 veins, the largest leaves are about 1/4 inch wide, but 7 to 20x longer than wide. These are much reduced in size near the top of the stem. Leaf tips are pointed and the bases taper to the stem attachment point. There will be a little gland-dotting on the surfaces.
The floral array is composed of branched flat-topped clusters at the top of the stems.
The flowers are composed of two types of florets: There are 17 to 22+ yellow ray florets which are pistillate and fertile. These surround a smaller number (5 to 7+) of disc florets that have yellow tubular corollas with 5 lobes; the lobes are erect to ascending when in flower. The disc florets are bisexual and fertile. They have 5 stamens and a branched style, with lanceolate shaped appendages at the tips. The style appendage is exserted beyond the corolla when in flower. Stamens surround and are appressed to the style. The outside of the flowerhead has several series of phyllaries that usually have yellowish bases. The outer ones are ovate and usually with green tips; the inner oblong with rounded to obtuse tips.
Seed: Fertile flowers produce a dry ellipsoid cypsela with white fully pappus attached for wind dispersion. Seeds of Solidago usually require 60 days of cold stratification and light for germination.
Varieties: Over time several varieties of this species have been described but most authorities today such as Flora of North America and the Minnesota authorities at the U of M and the MN DNR do not recognize varieties but treat them as simple local ecotypes.
Habitat: Grass-leaved Goldenrod grows a rhizomatous root system, which allows the plant to form colonies vegetatively. It is not aggressive and can be out-competed by grasses and other prairie plants. It grows in moist to dry condition of prairies, meadows, roadsides and empty fields and lots. Full sun best.
Names: This species was formerly in the genus Solidago with the species name of graminifolia, but botanists have separated it out into Euthamia based on the arrangement of flower heads, the gland-dotted leaves and DNA data. The genus Euthamia is derived from two Greek words - eu for 'good' or 'well' and thama for 'crowded'; said to be referring to the branching pattern of the floral array which provides many dense flower clusters. The species graminifolia means 'with leaves resembling grass'. The author names for the plant classification: First to classify was 'L.' which refers to Carl Linnaeus (1707-1778), Swedish botanist and the developer of the binomial nomenclature of modern taxonomy. His work was updated by ‘Nutt.’ which refers to Thomas Nuttall (1786-1859) English botanist who lived and worked in America from 1808 to 1841. On his many expeditions he collected many species that had been originally collected by Louis and Clark but lost by them on their return journey.
Comparisons: The leaves of Riddell's Goldenrod, Solidago riddellii, are somewhat grass-like but there the leaves are folded toward the center vein, are not gland-dotted, and the upper leaves sheath the stem while the number of ray florets is much fewer - 7 to 9.
Above: 1st & 2nd photo - The floral array has a number of small somewhat flat-topped clusters of small flowers at the top of the stem. 3rd photo - The leaves are grass-like in dimension, ascending, and fairly thick on the stem.
Below: The more basal leaves (bottom) are much longer that the upper stem leaves (top leaf).
Below: 1st photo - The outside of the flowerhead has several series of phyllaries that usually have yellowish bases. The greenish tips of these older heads have faded as the heads produce seed. 2nd photo - Stems are usually smooth and hairless with some darker color vertical lines. Note the leaves are stalkless but not clasping. 3rd photo - The underside of the leaf is much paler in color and has sparse hair on the mid-vein. Note the fine stiff hair on the margins.
Below: Note how the upper leaves are very 'grass-like' and also note the appendages on the styles of the disc florets.
Notes: Grass-leaved Goldenrod is indigenous to the Garden area. Eloise Butler catalogued it on Sept. 6, 1907. It is native to most counties in Minnesota except the very SE Corner. Within North America it is widespread, appearing in most of the U.S. except the SW states, and Texas, Florida, Georgia, Arkansas, Nebraska and Kansas. In Canada it is known in all the southern Provinces except Labrador.
There are two species of Euthamia found in Minnesota, E. graminifolia and The Great Plains Goldenrod, E. gymnospermoides. The latter species is much less widespread, mostly found in the metro and SE counties and a few counties in the SW. That species has more lanceolate leaves that are prominently gland-dotted and the flower clusters occupy more of the total plant height - 35 to 60%.
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.
Identification booklet for most of the flowering forbs and small flowering shrubs of the Eloise Butler Wildflower Garden. Details Here.
Friends of the Wild Flower Garden, Inc. Text and photos are by G. D. Bebeau unless otherwise credited. "www.friendsofthewildflowergarden.org"