Symphyotrichum tenuifolium |
Symphyotrichum sericeum |
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perennial saltmarsh American-aster, perennial saltmarsh aster |
silky aster, western silver aster, western silvery aster |
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Habit | Perennials, (20–)40–60(–100) cm, colonial or cespitose; rhizoma-tous. | Perennials, (20–)30–70 cm, cespitose, eglandular; with short, woody, cormoid caudices, or short rhizomes. | ||||
Stems | 1–5+, ascending to erect (often with purple or purplish brown areas, flexuous, wiry), little-branched, usually glabrous, sometimes hairy in lines distally. |
1–5+, ascending to erect (thin, grayish brown to dark brown), glabrous proximally, densely canescent distally. |
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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. |
(silvery) firm, soft; basal withering by flowering, sessile, blades (1–3 nerved) elliptic-lanceolate, 10–40 × 5–15 mm, bases cuneate, weakly sheathing, margins usually entire, rarely remotely serrate, piloso-ciliate, apices acute, faces less copiously hairy than cauline; proximal cauline withering by flowering, sessile, blades oblanceolate or oblong to linear-lanceolate, 15–30(–50) × 4–10 mm, slightly and progressively reduced distally, bases rounded, subclasping, margins entire, silky-pilose, apices obtuse to acute, mucronulate, faces sparsely to densely silky-pilose; distal sessile, blades lanceolate, 10–30 × 5–8 mm, little reduced distally, bases cuneate, margins entire, apices acute, mucronate, faces ± densely silky. |
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Peduncles | 0.6–4 (–6) cm, bracts 2–8, awl-shaped, grading into phyllaries. |
subsessile or 0.5–3(–5) cm, densely sericeo-strigose, bracts crowded, 4–8(–10) mm, grading into phyllaries. |
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Involucres | narrowly turbinate, 4.1–9.5(–11) mm. |
campanulate to cylindric, (5–)7.5–10 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. |
(10–)15–30; corollas usually rose-purple to deep purple, rarely white, laminae 8.5–11 × 1–1.5 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. |
(15–)25–35; corollas pink turning purple, (5–)5.5–7 mm, tubes shorter than narrowly funnelform throats (both thinly puberulent), lobes deltate, 0.7–0.9 mm. |
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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 3–5(–6) series, outer ovate with expanded distal portion [(4–)5–6 mm], mid ovate-lanceolate [6–8(–10) mm] with expanded green portions, inner linear, unequal or sometimes subequal, outer often foliaceous, bases (mid) scarious, margins silky, green zones restricted to expanded distal 1/2–2/3 (obscured by hairs), apices (outer) spreading or squarrose to reflexed, acute, mucronulate, faces densely long-silky. |
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Heads | (1–)3–20(–40), in open, diffuse, paniculiform arrays, branches patent. |
in open, paniculiform arrays, branches sparse, fastigiate, often arching (1–5+ per branch). |
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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. |
purple or brown, obovoid, not compressed, 2–3 mm, 7–10-nerved (prominent), faces glabrous; pappi whitish or tawny, 6–7 mm. |
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2n | = 10, 20. |
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Symphyotrichum tenuifolium |
Symphyotrichum sericeum |
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Phenology | Flowering Aug–Oct. | |||||
Habitat | Open, dry, deep, sandy or loamy soils, broken limestone outcrops, open-wooded bluffs, open woods, open calcareous hammocks, prairies, fields, sand barrens, dunes, dry banks, rarely acidic shield rocks | |||||
Elevation | 100–500+ m (300–1600+ 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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AR; GA; IA; IL; IN; KS; MI; MN; MO; ND; NE; OH; OK; SD; TN; TX; WI; MB; ON; West Indies (Bahamas)
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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 sericeum is known in the Bahamas as S. lucayanum (Britton) G. L. Nesom [syn. Aster lucayanus Britton, Virgulus lucayanus (Britton) Reveal & Keener]. It is of conservation concern in Indiana, Michigan, and Canada. Symphyotrichum sericeum is distinct and unlikely to be confused with other species due to its silvery-silky leaves and phyllaries, open arrays, and cormoid rootstocks. Aster sericeus forma albiligulatus Fassett is a white form of the species, in contrast to the typically purple forma sericeus; these do not deserve formal recognition. (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. 494. | ||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium | Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aster tenuifolius | Aster sericeus, Lasallea sericea, Virgulus sericeus | ||||
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 293. (1995) | (Ventenat) G. L. Nesom: Phytologia 77: 291. (1995) | ||||
Web links |