Short's Aster is an erect, native perennial forb growing from one to six feet high. Stems have fine vertical ridges, green with some reddish tones near the base, and can be finely hairy in the lower section, more so in the upper parts. There is little branching below the floral array.
The leaves are generally lance-like to slightly ovate and vary in size from basal to those in the floral array. Most leaves are usually without teeth but the larger leaves, up to 4+ inches long, have margins that curl a bit. Leaf bases are heart-shaped and tips taper to slender point. Lower and mid-stem leaves have a stalk, usually with a thin wing and marginal hair. The upper leaves will be without a stalk and the partially heart-shaped base will appear to be clasping the stem. These are much smaller and the margins are hairy. The upper surfaces are usually with hair, but the undersides have very fine hair with longer hair on the main veins. The lowest leaves will usually be withered away at flowering time.
The floral array is a much-branched panicle with arching to ascending branches of clusters of flower heads. The inflorescence is usually so large and heavy the the plant leans over. The panicle is very leafy with the small stalkless upper leaves and branches and stems are hairy.
The flowers are of two types - an outer group of 13 to 15+ ray florets which have light blue to purple-blue (seldom pinkish or whitish) rays, 1 to 1 1/2 inches across the open head. These are pistillate and fertile. Styles have a bifurcated tip. These surround the central disc florets which are tubular, yellow, and number 16 to 23 (28); these are bisexual and fertile. These florets have 5 triangular lobes on the open throats and turn color toward reddish purple at maturity. Disc florets open from the edge of the disc first then toward the center. Anthers are a reddish brown and the five stamens are appressed against the style. Flower stalk bracts number 3 to 10+, are green, ovate to lanceolate in shape and may be slightly spreading on the stalk, with fine stiff hairs. These grade into 4 to 5 series of phyllaries around the flowerhead. These are usually appressed, linear to lanceolate in shape, unequal in size. They are generally very light green with whitish margins but have a short, dark green, pointed tip, sometimes diamond shaped, and have stiff, but fine, surface and marginal hair.
Seed: Flowers are insect pollinated. Fertile flowers produce a 4 to 7 nerved dry purplish to brown oblong cypsela with reddish-brown to tawny to rose-tinged pappus attached for wind dispersion. Seeds are very fine, about 60,000 to the ounce and require 30 days of cold stratification for germination.
Habitat: Short's Aster grows from a rhizomatous and fibrous root system which can generate vegetatively new plants. The species needs fertile soil, mesic to dry-mesic moisture conditions and partial to full shade. Avoid full sun - partial shade is best for flowering. This species is late flowering, usually not until mid-September in central Minnesota.
Names: All the new world asters, formerly in the genus Aster, have now been reclassified, most into the genus Symphyotrichum. The genus name is from the Greek symphysis, for 'junction', and 'trichos', for hair, all of which relates to a fine division by botanists of certain plant characteristics. The species name, shortii, is an honorary for Charles Wilkins Short, (1794-1863), American doctor and botanist, professor of medical botany, then Professor Emeritus of Materia Medica and Medical Botany at the University of Louisville, where he had helped establish the medical school. He discovered a number of plant species, was considered the most well-known botanist in his part of the country in the middle 1800s, wrote A Catalogue of the Native Phaenogamous Plants and Ferns of Kentucky, maintained an extensive herbarium of over 15,000 plants, and has five species and one genus named for him.
The author names for the plant classification are as follows: ‘Lindl.’ refers to John Lindley (1799-1865), English botanist who authored or co-authored a number of articles and books on plants, some with his own colored engravings, particularly interested in roses and orchids; active member of the Royal Horticultural Society, University professor. His work was later updated by ‘G. L. Nesom’ who is for Guy L. Nesom (b. 1945) American botanist who has published papers on the nomenclature of asters.
Comparisons: Asters are notorious to separate by species and Short's Aster falls into the blue flowered group of which there are several that may be confusing, of which the Sky Blue Aster, Symphyotrichum oolentangiense, could be mistaken in the leaves - but there only the lower leaves have heart shaped bases. The flowers and phyllaries are similar so look to the leaves. The Arrow-leaved Aster, Symphyotrichum urophyllum, while it has white flowers, have leaves with slightly heart-shaped bases, but with broader stalk wings. See the comparison photos below for leaf, flower and phyllary comparison.
Above: The flowering panicle of Short's Aster is very open and broad, frequently causing the plant to lean over with the weight. Drawing from Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions.
Below: The ray florets are a light purple-blue surrounding 16 to 23 yellow disc florets - both are fertile.
Below: The phyllaries of the flower head are a greenish-white with dark green pointed tips. Stems are ridged with fine hair. The undersurface of the leaf is much paler in color due to fine whitish hair.
Below: A comparison of the basal, mid-stem and upper stem leaves. The leaves within the inflorescence are much smaller and attach directly to the hairy green stems.
Below: A similar looking leaf is the lower stem leaf of White Arrowleaf Aster - but usually larger and with a more pronounced wing.
A comparison of 4 common blue-flowered asters. Above - the flowers, Below - the phyllaries.
Below: Second photo - small nerved seeds of Short's Aster.
Short's Aster was originally introduced to the Garden by Eloise Butler on Aug. 28, 1926 with plants from Waseca MN, with more plants on Sept. 4th. That was the only known planting of it until Curator Susan Wilkins replanted it in 2012. Short's Aster is quite rare in the wild in Minnesota, being known only from populations in 3 SE counties, Fillmore, Houston and Winona. This area is the Northwest limit of the plants range in North America. It is found in Ontario in Canada (but sparsely) then south from the Great Lakes to the Gulf, absent in New England, New York and New Jersey. It was listed on the Minnesota Threatened List in 1996 but as of 2013 it is listed as "Special Concern".
There are twenty-four species just of Symphyotrichum listed by the DNR and the U of M as being found in Minnesota, some with several subspecies.
Eloise Butler note: In 1915 Eloise wrote about the Asters in the Garden. This work was sent to The Gray Memorial Botanical Chapter, (Division D ) of the Agassiz Association for publication in the Asa Gray Bulletin. The Agassiz Association was founded in the late 1800‘s to be an association of local chapters that would combine the like interests of individuals and organizations in the study of Nature. In that essay she asked chapter members if any had roots of Short's Aster to exchange as she wanted to add it to the Garden. Evidently, they did not.
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"