Symphyotrichum pilosum |
Symphyotrichum robynsianum |
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aster poilu, awl American-aster, frost aster, hairy aster, hairy white Oldfield aster, Oldfield or frost weed or white Oldfield or hairy or hairy white Oldfield aster, white heath aster |
aster à longues feuilles, longleaf aster, Robyns' aster |
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Habit | Perennials cespitose, (5–)20–120(–150+) cm; with stout, branched caudices, sometimes long-rhizomatous. | Perennials, 10–80 cm, colonial; long-rhizomatous. | ||||
Stems | 1–5+, ascending to erect (straight, stout), glabrate to hirsuto-hispid or pilose, sometimes glabrous or hairy in lines (var. pringlei). |
1, erect (± flexuous, often reddish), glabrous, hairy in lines distally. |
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Leaves | thin, margins ciliate, apices acute to acuminate, mucronate, faces glabrous or ± hirsute (particularly on abaxial midveins); basal withering by flowering (new vernal rosettes developing at flowering), petiolate to subpetiolate (petioles winged, ciliate, bases sheathing), blades oblanceolate or obovate to spatulate, 10–60 × 5–15 mm, bases attenuate, margins sparsely crenate-serrate (mostly apically), apices obtuse to rounded; proximal cauline usually deciduous at flowering (often with axillary clusters of small leaves), petiolate or subpetiolate to subsessile (petioles narrowly to broadly winged, clasping), blades elliptic-oblanceolate or -oblong to linear-lanceolate or -oblanceolate, 40–102 × 5–25 mm, progressively reduced distally, bases attenuate to cuneate, ± clasping, margins entire to serrate, softly ciliate, apices attenuate, hyaline-spinulose; distal sessile, blades lance-oblong to linear-lanceolate to linear or linear-oblanceolate or linear-subulate, 10–100 × 1–8 mm, progressively reduced distally, branch leaves abruptly smaller, bases cuneate, margins entire or serrulate. |
stiff, margins sparsely serrulate or entire, ± revolute, scabrous, apices acute to acuminate, mucronulate, faces glabrous, sometimes midveins hairy; basal withering by flowering, long-petiolate, petioles narrowly winged, bases sheathing, blades lanceolate, ca. 20 × 3–5 mm, slightly attenuate to narrowly cuneate; proximal cauline withering by flowering, sessile or subpetiolate, blades linear-lanceolate to -oblanceolate, 100–200 × 4–8 mm, bases cuneate to attenuate, clasping; distal sessile, blades linear-lanceolate to linear, 10–110 × 1–7 mm, progressively reduced distally, bases cuneate to rounded, slightly clasping or not, margins entire. |
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Peduncles | 5–30(–50) mm, progressively shorter distally, glabrous or densely hispid, bracts 7–25+, appressed to ascending, sometimes ± spreading, linear to subulate, glabrate, ciliate or not, mucronate to apiculate, ± grading into phyllaries. |
glabrous or ± densely pilose in lines, bracts 1–4, linear, sometimes inrolled distally, clasping, ciliate, distal 1–2 often subtending and surpassing involucres. |
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Involucres | campanulate to cylindro-campanulate, (2.5–)3.5–5.1(–6.5) mm. |
campanulate, 5–8.5 mm. |
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Ray florets | (10–)16–28(–38); corollas usually white, rarely pinkish or bluish, laminae (4–)5.4–7.5(–11) × (0.4–)0.8–1.3(–1.7) mm. |
20–35; corollas dark blue-violet, seldom white, laminae 8–13 × 1–1.5 mm. |
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Disc florets | (13–)17–39(–67); corollas light yellow becoming reddish purple or brown, (2.5–)3–4.1(–5.5) mm, tubes much shorter than narrowly funnelform throats, lobes lanceolate, (0.4–)0.6–0.8(–1) mm. |
(18–)23–40; corollas yellow, 4–6.5 mm, tubes shorter than funnelform throats, lobes lanceolate, 0.8–1 mm. |
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Phyllaries | in 4–6 series, appressed or slightly spreading, oblong-lanceolate (outer) to linear (innermost) , unequal (rarely subequal), bases indurate 1/2–3/5, margins hyaline, scarious, erose, ± ciliolate distally, green zones lanceolate to lance-rhombic, apices acute or acuminate, involute, spinulose, faces glabrous or sparsely hirsutulous. |
in 3–4 series, oblong-lanceolate, subequal, bases indurate 1/3–3/4, margins scarious, erose, hyaline, ciliate proximally, sparsely ciliolate distally, green zones lanceolate to linear, sometimes outer ± foliaceous, apices acuminate to long-acuminate, often foliaceous, mucronate to apiculate, faces glabrous, eglandular. |
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Heads | in open, leafy, often pyramidal, paniculiform arrays, branches divaricate or branches 10 cm or less ascending, often arched and secund, sometimes racemiform. |
in elongate, open, narrow, paniculiform or racemiform arrays, branches ascending, short, leafy, branch leaves smaller and reduced distally (heads 1–3 per branch). |
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Cypselae | whitish or gray, oblong-obovoid, sometimes ± compressed, 1–1.5 × 0.5–0.7 mm, 4–6-nerved, faces sparsely strigillose; pappi white, 3.5–4 mm. |
tan, obovoid, compressed, ca. 2.2–2.4 mm, 5–6-nerved, faces sparsely strigillose; pappi pinkish, 7–8 mm. |
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2n | = 64, 80. |
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Symphyotrichum pilosum |
Symphyotrichum robynsianum |
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Phenology | Flowering Aug–Sep. | |||||
Habitat | Wet or damp, open, sandy, gravelly, or rocky grounds, often calcareous, cracks in rocky stream or lake shores, limestone alvars, seasonally wet glades and swales, jackpine outwash plains | |||||
Elevation | 10–400 m (0–1300 ft) | |||||
Distribution |
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; VA; VT; WI; WV; BC; NB; NS; ON; QC
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MI; MN; WI; MB; ON; QC
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Discussion | Varieties 2 (2 in the flora). The ecology and cytogeography of Symphyotrichum pilosum were summarized by J. G. Chmielewski and J. C. Semple (2001b). The species is often confused with S. ericoides, which inhabits the same kinds of open, prairie-like habitats; the latter can be distinguished by its smaller heads and spine-tipped phyllary apices. Because of that, the name Aster ericoides has been misapplied often in floras and in the horticultural trade. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The name Aster longifolius Lamarck has been misapplied to this taxon. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 511. | FNA vol. 20, p. 530. | ||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aster pilosus, Aster ericoides var. pilosus | Aster robynsianus | ||||
Name authority | (Willdenow) G. L. Nesom: Phytologia 77: 289. (1995) | (J. Rousseau) Brouillet & Labrecque: Phytologia 82: 138. (1997) | ||||
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