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White Arrowleaf Aster

Symphyotrichum urophyllum (DC.) G. L. Nesom

Comments

provided by eFloras
The name Aster sagittifolius Wedemeyer ex Willdenow has been misapplied to this taxon; our interpretation of the type of this entity concords with that of A. G. Jones (1980), i.e., that it is conspecific with the type of Symphyotrichum cordifolium or a garden hybrid involving the latter. Aster sagittifolius forma hirtellus (Lindley) Shinners is not recognized here.
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Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA
bibliographic citation
Flora of North America Vol. 20: 468, 500, 502, 504, 506, 509, 525 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008.
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Flora of North America @ eFloras.org
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Flora of North America Editorial Committee
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Description

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Perennials, 40–120(–200) cm, cespitose; short-rhizomatous or with stout, branched caudices. Stems 1–5+, erect (straight to slightly flexuous, brittle, sometimes stout), proximally glabrous or glabrate, distally sparsely pilose. Leaves thin, margins usually shallowly, sometimes deeply serrate, rarely entire (distal), (piloso- to strigoso-)ciliate to scabrous (distal), apices mucronate, abaxial faces moderately pilose, ± densely so on midveins, adaxial glabrate to sparsely pilose or scabrous; basal usually withering by flowering, sometimes persistent, long-petiolate (5–15 cm, petioles not or narrowly winged, sheathing), blades ovate to lance-ovate or lanceolate, 25–120 × 15–50 mm, bases usually shallowly, sometimes deeply, cordate to truncate or rounded, apices acute, sometimes rounded; proximal cauline sometimes deciduous at flowering, winged-petiolate (petioles distally usually broader-winged, clasping), blades ovate to lanceolate, 50–120 × 20–50 mm, gradually reduced distally, bases usually truncate or rounded to attenuate, sometimes cordate, apices usually acute or acuminate, sometimes nearly caudate; distal ± shortly winged-petiolate or sessile, blades lance-ovate or lanceolate to linear-lanceolate, 10–100 × 1–25 mm, reduced distally, bases attenuate to cuneate, margins entire to subentire, scabrous, apices acuminate to subcaudate. Heads (crowded) in dense, elongate, paniculiform arrays, branches stiffly ascending to erect (sometimes arched when long, peduncles then often secund), usually racemiform, sometimes paniculiform, leafy. Peduncles 0.3–2 cm, sparsely pilosulous to glabrate, bracts many, ascending, linear to subulate, 2–4 mm, grading into phyllaries. Involucres cylindric, (4–)4.5–6(–7) mm. Phyllaries in 4–6 series, appressed or recurved-spreading, subulate (outer) to linear-lanceolate (inner), unequal, bases indurate 1 / 3 – 1 / 2 +, margins scarious, hyaline, erose, sparsely ciliolate (mostly distally), green zones linear-lanceolate (outer) to linear (inner), apices long-acuminate to caudate, recurved, hyaline-mucronate to aristate, tips often purple, faces glabrous. Ray florets 8–15(–20); corollas mostly white to pale pink or lilac or light blue, laminae 4.5–8(–10) × 0.8–1.5 mm. Disc florets (8–)10–15(–20); corollas whitish to cream becoming pink, (3.5–)4–5 mm, tubes shorter than funnelform throats (with hairs), lobes lanceolate, 0.4–0.7 mm. Cypselae tan to brown or dull purple (nerves stramineous), obovoid, ± compressed, 1.8–2.5 mm, 4–6-nerved, faces glabrous or glabrate or very sparsely strigillose; pappi white or rose-tinged, 3–4 mm. 2n = 16.
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cc-by-nc-sa-3.0
copyright
Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA
bibliographic citation
Flora of North America Vol. 20: 468, 500, 502, 504, 506, 509, 525 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008.
source
Flora of North America @ eFloras.org
editor
Flora of North America Editorial Committee
project
eFloras.org
original
visit source
partner site
eFloras

Synonym

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Aster urophyllus Lindley ex de Candolle in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 233. 1836; A. sagittifolius Wedemeyer ex Willdenow var. dissitiflorus E. S. Burgess
license
cc-by-nc-sa-3.0
copyright
Missouri Botanical Garden, 4344 Shaw Boulevard, St. Louis, MO, 63110 USA
bibliographic citation
Flora of North America Vol. 20: 468, 500, 502, 504, 506, 509, 525 in eFloras.org, Missouri Botanical Garden. Accessed Nov 12, 2008.
source
Flora of North America @ eFloras.org
editor
Flora of North America Editorial Committee
project
eFloras.org
original
visit source
partner site
eFloras

Symphyotrichum urophyllum

provided by wikipedia EN

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.[3]

Description

Leaf of S. urophyllum, Ontario, Canada

Symphyotrichum urophyllum is a perennial, herbaceous species between 40 and 120 centimeters (1+14 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.[4] The ray florets are white and the disc florets are white to cream becoming pink.[3]

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.[5]

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.[3][6]

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.[3]

Citations

References

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Symphyotrichum urophyllum: Brief Summary

provided by wikipedia EN

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.

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Wikipedia authors and editors
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wikipedia EN