Symphyotrichum spathulatum (formerly Aster spathulatus) is a species of flowering plant in the family Asteraceae native to western North America including northwestern Mexico. Commonly known as western mountain aster, it is a perennial, herbaceous plant that may reach 20 to 80 centimeters (8 to 31 inches) tall. Its flowers, which open in July and August, have violet ray florets and yellow disk florets.[5]
| Symphyotrichum spathulatum | |
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Scientific classification 
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| 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. Occidentales |
| Species: | S. spathulatum
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| Binomial name | |
| Symphyotrichum spathulatum | |
| Varieties[2] | |
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List
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| Native distribution[2] | |
| Synonyms[2] | |
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Basionym
Species
Varieties | |
Description
editSymphyotrichum spathulatum blooms in July and August and is a colony-forming perennial that grows typically 1–5 hairless or mostly hairless stems from a long rhizome. It ranges from 20 to 80 centimeters (8 to 31 inches) in height and has thin, entire leaves with little to no hair that are 5 to 15 centimeters (2 to 6 inches) long. The leaves are linear or elliptical, narrow, and sometimes obovate at the base of the plant. The upper leaves are shorter at 3 to 6 centimeters (1+1⁄8 to 2+3⁄8 inches).[5]
The flower heads grow in corymbiform to paniculiform arrays with little branching. The involucres are 5–10 millimeters (1⁄5–2⁄5 inch) and bell-shaped, and their phyllaries are in 3–5 series. There are 15–40 violet ray florets that are 9–15 millimeters (7⁄20–3⁄5 inch) long and 1–2 millimeters (1⁄20–1⁄10 inch) wide. These surround the flower centers composed of 30–80 (sometimes up to 100) yellow disk florets.[5]
The seeds are brown, hairy cypselae 2.5–3.5 mm (1⁄10–3⁄20 in) long with about 4 nerves and white pappi that are 5–7 millimeters (1⁄5–3⁄10 inch) long.[5]
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Chromosomes
editSymphyotrichum spathulatum has a base number of x = 8.[6] Diploid, tetraploid, hexaploid, and octaploid cytotypes with respective chromosome counts of 16, 32, 48, and 64 have been reported, depending upon the infraspecies, as follows:
Taxonomy
editSymphyotrichum spathulatum is one of the species within Symphyotrichum sect. Occidentales.[a][11] S. spathulatum was first formally described by John Lindley in 1834 as Aster spathulatus.[12]
Three varieties of Symphyotrichum spathulatum are recognized, including the autonym:[5]
- S. spathulatum var. spathulatum
- S. spathulatum var. intermedium
- S. spathulatum var. yosemitanum
S. spathulatum is one of the parents of the two allopolyploidal Symphyotrichum species S. ascendens[13] and S. defoliatum.[14]
Distribution and habitat
editSymphyotrichum spathulatum is found in the western United States, western Canada, and northwestern Mexico. It is native to British Columbia and Alberta in Canada, and in the United States from Washington state east to Montana, south to New Mexico, west to California, and north again to Oregon. There is no recorded presence in Arizona. In Mexico, it is native to the states bordering the Gulf of California.[2] It grows at 1,200–2,900 meters (3,900–9,500 feet) (or lower) in meadows on mountain slopes and open aspen and coniferous forests.[7]
S. spathulatum var. intermedium is native to British Columbia, California, Idaho, Nevada, Oregon, and Washington state,[3] only occasionally being found in California and Nevada. It grows at 1,200–2,200 m (3,900–7,200 ft) in grasslands and meadows on mountain slopes and in open coniferous forests.[8]
S. spathulatum var. yosemitanum is restricted from southern Oregon to the Sierra Nevada of California. It can be found at 1,200–2,200 m (3,900–7,200 ft) in oak woodlands and coniferous forests.[15]
Conservation
editAs of July 2021[update], NatureServe listed Symphyotrichum spathulatum as Secure (G5) worldwide and Possibly Extirpated (SX) in Alberta.[1] S. spathulatum var. intermedium and S. spathulatum var. spathulatum were reported as Secure Varieties (T5),[16][17] and no status rank was given for S. spathulatum var. yosemitanum.[18]
Notes
edit- ^ Occidentales is listed as a section in Flora of Missouri,[10] whereas on Canadian botanist John C. Semple's Astereae Lab website, it is given as a subsection of section Symphyotrichum.[11]
Citations
edit- ^ a b NatureServe 2021a.
- ^ a b c d e POWO 2021a.
- ^ a b POWO 2021b.
- ^ POWO 2021c.
- ^ a b c d e Brouillet et al. 2006a.
- ^ Semple n.d.a.
- ^ a b Brouillet et al. 2006c.
- ^ a b Brouillet et al. 2006b.
- ^ Allen 2012.
- ^ Yatskievych n.d.
- ^ a b Semple 2021a.
- ^ IPNI 2021.
- ^ Semple 2021b.
- ^ Semple n.d.b.
- ^ Brouillet et al. 2006d.
- ^ NatureServe 2021b.
- ^ NatureServe 2021c.
- ^ NatureServe 2021d.
References
edit- Allen, G.A. (2012). "Symphyotrichum spathulatum var. yosemitanum". In Jepson Flora Project (ed.). Jepson eFlora. The Jepson Herbarium, University of California, Berkeley. Retrieved 23 September 2022.
- Brouillet, L.; Semple, J.C.; Allen, G.A.; Chambers, K.L.; Sundberg, S.D. (2006a). "Symphyotrichum spathulatum". 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 23 July 2021 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Brouillet, L.; Semple, J.C.; Allen, G.A.; Chambers, K.L.; Sundberg, S.D. (2006b). "Symphyotrichum spathulatum var. intermedium". 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 23 July 2021 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Brouillet, L.; Semple, J.C.; Allen, G.A.; Chambers, K.L.; Sundberg, S.D. (2006c). "Symphyotrichum spathulatum var. spathulatum". 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 23 July 2021 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- Brouillet, L.; Semple, J.C.; Allen, G.A.; Chambers, K.L.; Sundberg, S.D. (2006d). "Symphyotrichum spathulatum var. yosemitanum". 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 23 July 2021 – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
- IPNI (2021). "Aster spathulatus Lindl". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Botanic Gardens. Retrieved 22 July 2021.
- NatureServe (2 July 2021a). "Symphyotrichum spathulatum Western Mountain Aster". explorer.natureserve.org. Arlington, Virginia. Retrieved 11 July 2021.
- NatureServe (2 July 2021b). "Symphyotrichum spathulatum var. intermedium". explorer.natureserve.org. Arlington, Virginia. Retrieved 23 July 2021.
- NatureServe (2 July 2021c). "Symphyotrichum spathulatum var. spathulatum". explorer.natureserve.org. Arlington, Virginia. Retrieved 23 July 2021.
- NatureServe (2 July 2021d). "Symphyotrichum spathulatum var. yosemitanum". explorer.natureserve.org. Arlington, Virginia. Retrieved 23 July 2021.
- POWO (2021a). "Symphyotrichum spathulatum (Lindl.) G.L.Nesom". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 22 July 2021.
- POWO (2021b). "Symphyotrichum spathulatum var. intermedium (A.Gray) G.L.Nesom". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 22 July 2021.
- POWO (2021c). "Symphyotrichum spathulatum var. yosemitanum (A.Gray) G.L.Nesom". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 22 July 2021.
- Semple, J.C. (n.d.a). "Symphyotrichum subsect. Occidentales Foliacei Asters". www.uwaterloo.ca. Ontario. Archived from the original on 28 June 2021. Retrieved 23 July 2021.
- Semple, J.C. (n.d.b). "Symphyotrichum subg. Ascendentes". www.uwaterloo.ca. Ontario. Archived from the original on 22 July 2021. Retrieved 22 July 2021.
- Semple, J.C. (17 May 2021a). "Classification of Symphyotrichum". www.uwaterloo.ca. Ontario. Archived from the original on 21 June 2021. Retrieved 23 July 2021.
- Semple, J.C. (14 May 2021b). "Symphyotrichum ascendens — Long-leaved Aster, Intermountain Aster, Western Aster". www.uwaterloo.ca. Ontario. Archived from the original on 22 July 2021. Retrieved 22 July 2021.
- Yatskievych, G., ed. (n.d.). "Symphyotrichum sect. Occidentales (Rydb.) G.L. Nesom". Flora of Missouri. Missouri Botanical Garden. Retrieved 23 July 2021 – via Tropicos.org.