General: Aster Family (Asteraceae). Smooth blue aster is a perennial forb with a stout rhizome and underground stem (caudex). Six to seven aerial stems sprout from the caudex. Plants are generally 30 to 100 cm tall. Leaves are thick and stout, 1 to 2.4 cm wide and less than 5 times as long as wide, sometimes toothed along the margins and clasped to the stem by a lobed appendage (auricle). Leaves near the inflorescence are reduced to 2 mm bracts and have diamond-shaped tips. Each plant produces several inflorescences. Ray flowers are pale blue to purple, 7 to 15 mm long. Disc flowers are yellowish. Fruit are achenes. Flowering occurs from August to October. Lower leaves drop early in the autumn while upper leaves remain until frost top-kills the plant.
Distribution: Smooth blue aster is native to the United States. It occurs from Maine to British Columbia, south to Georgia and Arkansas, and west to New Mexico. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site.
Habitat: Smooth blue aster occurs in various habitats, ranging from moist woods to dry, open prairies. It is most notably associated with mixed prairie plant types, and is also a dominant understory species in quaking-aspen communities.
Aster falcidens var. falcatus, Aster laevis, Aster laevis forma amplifolius, Aster laevis forma latifolius, Aster laevis forma purpurascens, Aster laevis var. amplifolius, Aster laevis var. falcatus, Aster laevis var. latifolius, Aster laevis var. thyrsoideus, Aster steeleorum, Smooth aster, Symphyotrichum laeve
Regularity: Regularly occurring
Regularity: Regularly occurring
USDA hardiness zones for smooth blue aster are 4 to 8. Smooth blue aster occurs on various soil types. It was found to sustain more populations on wet, poorly drained glacial till in eastern Illinois and western Indiana. In Michigan it occurs on xeric sites more readily than on mesic and transitional sites. It is not tolerant of deep shade, but does well in high light to intermittent shade conditions.
Smooth blue aster seeds are ready for collection in September when achenes separate easily from the receptacle. Dry seeds prior to cleaning and store in sealed containers at 3 to 5oC. Damp stratification at 1 to 2oC for 2.5 to 4 months may increase seed germination of higher elevation sources. Seed storage longevity is up to 7 years.
Seeds can be started in the greenhouse from December to March. Cover seeds to one times their depth with soil and lightly press down. Seeds germinate in 10 to 15 days at 22oC, reaching the true leaf stage in 7 to 15 days. Seedlings should be thinned and fertilizer can be applied biweekly once the true leaf stage has been reached. Foliage must be thoroughly rinsed off after fertilizer application. When foliage is 8 to 10 inches tall, prune plants back to 3 to 4 inches.
For the first 12 weeks, 20-10-20 liquid NPK fertilizer at 100 ppm is applied. Plants are then fertilized once with 10-20-20 liquid NPK at 200 ppm. After 4 weeks, seedlings can be stored in outdoor temperatures under insulating foam (if necessary) for up to 5 months before outplanting. Outplanting can take place from September to November or April to May.
Flower-Visiting Insects of Smooth Blue Aster in Illinois
(Bees collect pollen or suck nectar; flies and beetles suck nectar or feed on pollen; other insects suck nectar; most observations are from Graenicher, although some observations are from Petersen, Hilty, Swengel & Swengel, and Tuell et al. as indicated below)
Apidae (Apinae): Apis mellifera sn (Gr, Pt, Tll); Apidae (Bombini): Bombus bimaculatus (Pt), Bombus griseocollis sn, Bombus impatiens fq (Tll), Bombus pensylvanicus sn, Bombus vagans sn, Psithyrus citrinus sn; Anthophoridae (Ceratinini): Ceratina dupla dupla sn cp; Anthophoridae (Epeolini): Triepeolus cressonii cressonii sn, Triepeolus helianthi helianthi sn, Triepeolus lunatus concolor sn; Anthophoridae (Eucerini): Melissodes desponsa sn, Melissodes rustica sn cp; Anthophoridae (Xylocopini): Xylocopa virginica sn cp; Megachilidae (Coelioxini): Coleioxys moesta sn, Coelioxys octodentata sn; Megachilidae (Megachilini): Megachile centuncularis sn cp, Megachile mendica sn
Halictidae (Halictinae): Agapostemon sericea sn cp, Agapostemon virescens sn cp (Gr, Tll), Augochlorella striata sn, Halictus confusus sn, Halictus rubicundus sn, Lasioglossum coriaceum sn, Lasioglossum cressonii sn, Lasioglossum forbesii sn, Lasioglossum tegulare sn; Colletidae (Colletinae): Colletes compactus sn; Colletidae (Hylaeinae): Hylaeus modestus modestus sn; Andrenidae (Andreninae): Andrena asteris sn cp olg, Andrena canadensis sn cp
Sphecidae (Sphecinae): Ammophila kennedyi, Prionyx atrata; Vespidae (Eumeninae): Parancistrocerus pedestris
Syrphidae: Eristalinus aeneus, Eristalis anthophorina, Eristalis brousii, Eristalis dimidiatus, Eristalis flavipes, Eristalis tenax, Eristalis transversus, Helophilus fasciatus, Helophilus latifrons, Platycheirus obscurus, Sphaerophoria contiqua, Spilomyia sayi, Syritta pipiens, Syrphus ribesii, Syrphus torvus, Toxomerus geminatus, Toxomerus marginatus, Tropidia quadrata; Conopidae: Thecophora abbreviata; Tachinidae: Spallanzania hesperidarum; Calliphoridae: Phormia regina, Pollenia rudis; Sarcophagidae: Sarcophaga sp.; Muscidae: Musca domestica, Neomyia cornicina, Stomoxys calcitrans
Nymphalidae: Danaus plexippus, Vanessa atalanta, Vanessa virginiensis; Pieridae: Colias philodice, Pieris rapae, Pontia protodice; Lycaenidae: Celastrina argiolus, Lycaeides melissa samuelis (Sw)
Hesperiidae: Polites peckius (Gr, H)
Noctuidae: Anagrapha falcifera
Carabidae (Lebiini): Lebia solea; Chrysomelidae: Acalymma vittata, Diabrotica undecimpunctata; Lampyridae: Ellychnia corrusca
Molecular Biology and Genetics
Statistics of barcoding coverage: Aster laevis
Public Records: 2
Specimens with Barcodes: 4
Species With Barcodes: 1
National NatureServe Conservation Status
Rounded National Status Rank: N5 - Secure
Rounded National Status Rank: N5 - Secure
NatureServe Conservation Status
Rounded Global Status Rank: T5 - Secure
Please consult the PLANTS Web site (http://plants. usda.gov) and your State Department of Natural Resources for this plant’s current status (e.g. threatened or endangered species, state noxious status, and wetland indicator values).
Comments: Lack of disturbance and succession are moderate threats to this species (Southern Appalachian Species Viability Project 2002).
Cultivars, improved and selected materials (and area of origin)
The NRCS Plant Materials Program has not released any cultivars of smooth blue aster for conservation use. Regional seed sources of native smooth blue aster are recommended for use in your area.
Contact your local Natural Resources Conservation Service (formerly Soil Conservation Service) office for more information. Look in the phone book under ”United States Government.” The Natural Resources Conservation Service will be listed under the subheading “Department of Agriculture.”
Deer grazing does not affect survival of established smooth blue aster plants, as long as only stem tips are removed. Most plants respond to grazing with vigorous growth the next growing season.
Herbicides used to control quack grass can suppress establishment or growth. These herbicides contain glyphosate, dichlobenil, picloram, tebuthiuron, and hexazinone, alone or in combination with each other.
Smooth blue aster resprouts from the rhizome after being top-killed by fire. In general, late spring fires have more adverse effects on percent plant coverage, and perhaps on leaf and flower regeneration, than early spring fires.
Relevance to Humans and Ecosystems
Conservation: Smooth blue aster is used for mixed-grass and tallgrass prairie restoration as well as roadside revegetation.
Gardening: The showy flowers of smooth blue aster makes it a popular plant for use in wildflower, native plant, and butterfly gardens.
Wildlife: Smooth blue aster is palatable to white-tailed deer, which prefer to graze this species before other forbs. It has high nutritional value, decreasing with maturation. It also attracts butterflies, pollinators of the flowers, and can provide shelter for them.
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