Symphyotrichum urophyllum

Symphyotrichum urophyllum
Conservation status
Apparently Secure  (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Asterales
Family:	Asteraceae
Tribe:	Astereae
Subtribe:	Symphyotrichinae
Genus:	Symphyotrichum
Subgenus:	Symphyotrichum subg. Symphyotrichum
Section:	Symphyotrichum sect. Symphyotrichum
Species:	S. urophyllum
Binomial name
Symphyotrichum urophyllum (Lindl.) G.L. Nesom
Native distribution
Synonyms
Basionym Aster urophyllus Lindl. Alphabetical list Aster hirtellus Lindl. ex DC. Aster sagittifolius var. dissitiflorus E.S.Burgess Aster sagittifolius var. glomerellus Farw. Aster sagittifolius f. hirtellus (Lindl. ex DC.) Shinners Aster sagittifolius var. urophyllus (Lindl. ex DC.) Burgess Aster urophyllus var. glomerellus Farw.

Symphyotrichum urophyllum (formerly Aster urophyllus) is a species of flowering plant in the family Asteraceae native to eastern North America, commonly known as arrowleaf aster.

Description

Leaf of S. urophyllum, Ontario, Canada

Symphyotrichum urophyllum is a perennial, herbaceous species between 40 and 120 centimeters (1+1⁄4 and 4 feet) tall. Plants are cespitose, with 1–5 erect stems emerging from the same point. The broad, thin, toothed leaves are arrow-shaped, with a broadly winged petiole. The dense, pyramidal inflorescence of composite flowers is distinctive. The ray florets are white and the disc florets are white to cream becoming pink.

Taxonomy

Symphyotrichum urophyllum was formerly included in the large genus Aster as Aster urophyllus. However, this broad circumscription of Aster is polyphyletic and the North American asters are now mostly classified in Symphyotrichum and several other genera.

The taxonomic status of this species has been unstable, and it has been treated as Symphyotrichum sagittifolium, a name now considered to be synonymous with Symphyotrichum cordifolium. Most sources now use S. urophyllum to refer to this species.

Distribution and habitat

S. urophyllum, Ontario, Canada, showing pyramidal inflorescence

Symphyotrichum urophyllum is native to the United States from Maine to Florida and west to Nebraska, as well as Ontario, Canada. It is found in open, dry to mesic habitats such as meadows, open woodlands, bluffs, forest edges, and roadsides.

References

• Brouillet, L.; Semple, J.C.; Allen, G.A.; Chambers, K.L.; Sundberg, S.D. (2006). "Symphyotrichum urophyllum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 20. New York and Oxford: Oxford University Press. Retrieved 3 July 2021 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
• Hilty, J. (2020). "White Arrowleaf Aster (Symphyotrichum urophyllum)". Illinois Wildflowers (www.illinoiswildflowers.info). Retrieved 28 January 2020.
• NatureServe (2 July 2021). "Symphyotrichum urophyllum White-arrow Aster". explorer.natureserve.org. Arlington, Virginia. Retrieved 3 July 2021.
• POWO (2019). "Symphyotrichum urophyllum (Lindl.) G.L.Nesom". powo.science.kew.org. Royal Botanic Gardens, Kew. Retrieved 3 July 2021.
• Reznicek, A.A.; Voss, E.G.; Walters, B.S., eds. (February 2011). "Symphyotrichum urophyllum". Michigan Flora Online. University of Michigan Herbarium. Retrieved 28 January 2020.
• Semple, J.C. (27 April 2021). "An overview of "asters" and the Tribe Astereae". www.uwaterloo.ca. Ontario. Archived from the original on 27 May 2021. Retrieved 3 July 2021.