Symphyotrichum tenuifolium |
Symphyotrichum retroflexum |
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perennial saltmarsh American-aster, perennial saltmarsh aster |
rigid whitetop aster |
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Habit | Perennials, (20–)40–60(–100) cm, colonial or cespitose; rhizoma-tous. | Perennials, 40–100 cm, usually colonial, sometimes ± cespitose; short-(seldom long-)rhizomatous. | ||||
Stems | 1–5+, ascending to erect (often with purple or purplish brown areas, flexuous, wiry), little-branched, usually glabrous, sometimes hairy in lines distally. |
1–2+, erect (straight to slightly flexuous, sometimes robust), glabrous. |
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Leaves | thick (fleshy), margins entire, faces glabrous; basal withering by flowering (new winter rosettes appearing at flowering), petiolate (petioles sheathing), blades ovate or oblanceolate, 15–20 × 5–15 mm, bases cuneate, apices rounded; proximal cauline withering by flowering, usually sessile, blades lanceolate, linear-lanceolate or -oblanceolate, to linear, 7–80(–150) × 1–6 (–12) mm, bases attenuate, margins entire, apices acuminate to acute; distal sessile, blades narrowly lanceolate to subulate, 10–110 × 0.5–5 mm, apices acuminate. |
thin to firm, margins slightly recurved, scabrous, faces glabrous; basal mostly withering by flowering, petiolate (petioles narrowly winged, sheathing), blades lanceolate-ovate to ovate or spatulate, 25–110 × 10–40 mm, bases usually rounded to attenuate, seldom ± cordate, margins serrulate to shallowly serrate, apices obtuse to acute; proximal cauline often withering by flowering, petiolate (petioles ± widely winged, ± clasping), blades lance-ovate or narrowly ovate, 50–95 × 19–31 mm, bases usually rounded to attenuate, sometimes cuneate, rarely subcordate, margins serrate to serrulate; distal winged-petiolate or subpetiolate or sessile, blades lance-ovate or narrowly ovate to lanceolate or sometimes linear (in arrays), 7–1.5 × 3–31 mm, gradually and strongly reduced distally, bases cuneate, scarcely or not clasping, to slightly rounded and ± clasping, margins serrulate or entire, apices acute to acuminate. |
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Peduncles | 0.6–4 (–6) cm, bracts 2–8, awl-shaped, grading into phyllaries. |
(when present) 0.2–1.5 cm, densely pilose or pilosulous, bracts 1–6+, lanceolate to oblong-lanceolate, foliaceous to distally grading into phyllaries. |
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Involucres | narrowly turbinate, 4.1–9.5(–11) mm. |
campanulate, (6–)7–10 mm. |
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Ray florets | 10–25; corollas white or pink, laminae (4.5–)5–8.5(–9.5) × 1.2–2 mm. |
13–30; corollas blue to purple, laminae (10–)15–17 × 1.6–3 mm. |
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Disc florets | 25–45(–54); corollas yellow becoming purplish, 3.4–6(–6.8) mm, tubes shorter than to equaling the narrowly funnelform throats (sparsely hairy at base), lobes ± erect, narrowly triangular, 0.5–0.8 mm. |
35–50+; corollas cream to pale yellow becoming pinkish, 5.8–6.8 mm, tubes shorter than funnelform throats, lobes lanceolate, 0.9–1.2 mm, glabrous. |
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Phyllaries | in 4–5 series, lanceolate to subulate, bases indurate, rounded, margins hyaline, often tinged with purple, entire, green zones spatulate to oblanceolate-rhombic, apices acute, adaxial faces glabrous or minutely hairy distally. |
in 3–4(–5) series, broadly lanceolate constricted to narrow oblong bases (outer) to oblong-lanceolate or linear-lanceolate (inner), ± unequal, bases indurate 1/10–1/5 (outer) to 4/5+ (inner), margins hyaline, narrowly scarious, erose (indurate portion), sparsely ciliolate (foliaceous portion), green zones foliaceous (outer) to distal 1/5–1/4 foliaceous (inner), basally truncate to lanceolate, apices spreading to squarrose, acute to acuminate, mucronulate, abaxial faces glabrous or glabrate, adaxial strigillose (foliaceous portion). |
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Heads | (1–)3–20(–40), in open, diffuse, paniculiform arrays, branches patent. |
in broad (appearing ± corymbiform) or narrow, paniculiform to ± racemiform arrays, branches usually long (to 10 cm), ascending to divaricate. |
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Cypselae | light brown, narrowly obovoid to fusiform, sometimes ± compressed, 1.5–4(–4.5) mm, 5–6-nerved, faces sparsely strigillose; pappi tawny to white, 3–6.1 mm. |
tan, obovoid to oblanceoloid, compressed, 3–3.9 mm, 4–6-nerved, faces glabrous or sparsely strigillose; pappi whitish to reddish, 5.3–6 mm. |
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2n | = 48. |
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Symphyotrichum tenuifolium |
Symphyotrichum retroflexum |
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Phenology | Flowering Aug–Oct. | |||||
Habitat | Moist meadows, moist woodlands, dry, open, pine or oak woods, wooded roadsides | |||||
Elevation | 400–1500 m (1300–4900 ft) | |||||
Distribution |
AL; CT; DE; FL; GA; LA; MA; MD; ME; MS; NC; NH; NJ; NY; RI; SC; TX; VA; West Indies
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AL; GA; NC; SC; TN; VA
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Discussion | Varieties 2 (2 in the flora). Along the Gulf of Mexico Coast in central and northern peninsular Florida, vars. tenuifolium and aphyllum intergrade in nearly all characters (S. D. Sundberg 2004). G. L. Nesom (2005d) treated the varieties as species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Symphyotrichum retroflexum is known only from the Appalachian Blue Ridges. It is possible that the species is an allopolyploid derived from members of subsections Cordifolii and Symphyotrichum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 479. | FNA vol. 20, p. 510. | ||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aster tenuifolius | Aster retroflexus, Aster curtisii | ||||
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 293. (1995) | (Lindley ex de Candolle) G. L. Nesom: Phytologia 77: 291. (1995) | ||||
Web links |