Biology:Symphyotrichum spathulatum

Short description: Species of flowering plant in the family Asteraceae native to western North America including Mexico

Symphyotrichum spathulatum
Conservation status
Invalid status (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. Occidentales
Species:	S. spathulatum
Binomial name
Symphyotrichum spathulatum (Lindl.) G.L.Nesom
Varieties
List S. spathulatum var. spathulatum S. spathulatum var. intermedium (A.Gray) G.L.Nesom S. spathulatum var. yosemitanum (A.Gray) G.L.Nesom
Native distribution
Synonyms
Basionym Aster spathulatus Lindl. Species Aster occidentalis var. typicus Rothr. Aster ascendens var. delectabilis (H.M.Hall) Jeps. Aster ascendens var. fremontii Torr. & A.Gray Aster delectabilis H.M.Hall A.Gray Cockerell A.Gray Cockerell (H.M.Hall) Ferris (A.Gray) Ferris Cronquist Nutt. Aster occidentalis Aster occidentalis var. fremontii Aster occidentalis var. scabriusculus Symphyotrichum spathulatum var. fremontii Aster fremontii Aster fremontii f. pallidus Aster fremontii var. parishii Aster fremontii f. viridus Torr. & A.Gray (Torr. & A.Gray) A.G.Jones A.Gray (Torr. & A.Gray) G.L.Nesom Aster aestivus Aster occidentalis var. delectabilis Aster occidentalis var. parishii Tripolium occidentale Varieties var. intermedium Aster vallicola Aster occidentalis var. intermedius A.Gray (A.Gray) Piper Greene Aster spathulatus var. intermedius Aster occidentalis subsp. intermedius (A.Gray) Cronquist var. yosemitanum Aster yosemitanus Aster ascendens var. yosemitanus A.Gray (A.Gray) Cronquist Greene Aster paludicola Aster occidentalis var. yosemitanus Piper

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.

Description

Symphyotrichum 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).

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.

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.

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Chromosomes

Symphyotrichum spathulatum has a base number of x = 8. 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:

• S. spathulatum var. spathulatum: 2n = 2x = 16, 2n = 4x = 32, 2n = 6x = 48, and 2n = 8x = 64
• S. spathulatum var. intermedium: 2n = 4x = 32, 2n = 6x = 48, and 2n = 8x = 64
• S. spathulatum var. yosemitanum: 2n = 2x = 16, 2n = 4x = 32

Taxonomy

Symphyotrichum spathulatum is one of the species within Symphyotrichum sect. Occidentales. S. spathulatum was first formally described by John Lindley in 1834 as Aster spathulatus.

Three varieties of Symphyotrichum spathulatum are recognized, including the autonym:

• 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 and S. defoliatum.

Distribution and habitat

Symphyotrichum 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. 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.

S. spathulatum var. intermedium is native to British Columbia, California, Idaho, Nevada, Oregon, and Washington state, 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.

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.

Conservation

(As of July 2021), NatureServe listed Symphyotrichum spathulatum as Secure (G5) worldwide and Possibly Extirpated (SX) in Alberta. S. spathulatum var. intermedium and S. spathulatum var. spathulatum were reported as Secure Varieties (T5), and no status rank was given for S. spathulatum var. yosemitanum.

References

• Template:Cite Jepson eFlora
• Flora of North America Editorial Committee, ed. (2006a), "Symphyotrichum spathulatum", Flora of North America North of Mexico (FNA), 20, New York and Oxford, http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250067687, retrieved 23 July 2021 
• Flora of North America Editorial Committee, ed. (2006b), "Symphyotrichum spathulatum var. intermedium", Flora of North America North of Mexico (FNA), 20, New York and Oxford, http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250068859, retrieved 23 July 2021 
• Flora of North America Editorial Committee, ed. (2006c), "Symphyotrichum spathulatum var. spathulatum", Flora of North America North of Mexico (FNA), 20, New York and Oxford, http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250068860, retrieved 23 July 2021 
• Flora of North America Editorial Committee, ed. (2006d), "Symphyotrichum spathulatum var. yosemitanum", Flora of North America North of Mexico (FNA), 20, New York and Oxford, http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250068861, retrieved 23 July 2021 
• "Aster spathulatus Lindl.". International Plant Names Index (IPNI). Royal Botanic Gardens, Kew. https://www.ipni.org/n/309149-2. 
• "Symphyotrichum spathulatum Western Mountain Aster" (in en). Arlington, Virginia. 2 July 2021a. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.131311/Symphyotrichum_spathulatum. 
• "Symphyotrichum spathulatum var. intermedium" (in en). Arlington, Virginia. 2 July 2021b. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.152019/Symphyotrichum_spathulatum_var_intermedium. 
• "Symphyotrichum spathulatum var. spathulatum" (in en). Arlington, Virginia. 2 July 2021c. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.158406/Symphyotrichum_spathulatum_var_spathulatum. 
• "Symphyotrichum spathulatum var. yosemitanum" (in en). Arlington, Virginia. 2 July 2021d. https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.133204/Symphyotrichum_spathulatum_var_yosemitanum. 
• POWO (2021a). "Symphyotrichum spathulatum (Lindl.) G.L.Nesom" (in en). Royal Botanic Gardens, Kew. http://www.plantsoftheworldonline.org/taxon/981901-1. 
• POWO (2021b). "Symphyotrichum spathulatum var. intermedium (A.Gray) G.L.Nesom" (in en). Royal Botanic Gardens, Kew. http://www.plantsoftheworldonline.org/taxon/981903-1. 
• POWO (2021c). "Symphyotrichum spathulatum var. yosemitanum (A.Gray) G.L.Nesom" (in en). Royal Botanic Gardens, Kew. http://www.plantsoftheworldonline.org/taxon/981904-1. 
• "Symphyotrichum subsect. Occidentales Foliacei Asters" (in en). Ontario. n.d.a. https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/symphyotrichum-subsect-occidentales. 
• "Symphyotrichum subg. Ascendentes" (in en). Ontario. n.d.b. https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/symphyotrichum-subg-ascendentes. 
• "Classification of Symphyotrichum" (in en). Ontario. 17 May 2021a. https://uwaterloo.ca/astereae-lab/research/asters/symphyotrichum/classification-symphyotrichum. 
• "Symphyotrichum ascendens — Long-leaved Aster, Intermountain Aster, Western Aster" (in en). Ontario. 14 May 2021b. https://uwaterloo.ca/astereae-lab/symphyotrichum-ascendens. 
• Template:Cite Tropicos

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