Symphyotrichum anticostense |
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Anticosti American-aster, Anticosti aster, Anticosti Island aster, aster d'Anticosti |
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Habit | Perennials, 10–90 cm, colonial; long-rhizomatous. |
Stems | 1, erect (straight, often reddish), glabrous. |
Leaves | coriaceous, margins remotely serrulate or entire, slightly revolute, scabrous, apices mucronulate, faces glabrous; basal withering by flowering, long-petiolate (petioles narrowly winged, bases sheathing), blades lanceolate to oblanceolate, ca. 55+ × 3+ mm, bases slightly attenuate, apices acute; proximal cauline mostly withering by flowering, petiolate (petioles narrowly winged, sheathing), blades lanceolate or oblanceolate to linear-lanceolate or -oblanceolate, arcuate, 90–160 × 5–18 mm, bases cuneate to slightly attenuate, margins entire or serrulate, apices acute; distal sessile, blades linear to linear-lanceolate, 8–50 × 1.5–5 mm, progressively reduced distally, more strongly so in arrays, bases cuneate to rounded, sometimes slightly clasping, apices acute to acuminate. |
Peduncles | 0.8–5.7 cm, slender, sparsely ot moderately pilosulous, bracts 3–5, linear-lanceolate, often crowded proximal to and surpassing heads. |
Involucres | campanulate, 6–10 mm. |
Ray florets | 25–44; corollas usually pale purple or lilac, sometimes white, laminae 9.5–20 × 0.7–1.4 mm. |
Disc florets | 29–52; corollas yellow becoming reddish purple, 5–6 mm, tubes slightly shorter than funnelform throats, lobes lanceolate, 0.6–0.7 mm. |
Phyllaries | in 2–3 series, oblong-oblanceolate or -spatulate (outer) or oblong-lanceolate to linear-lanceolate or linear (inner), ± unequal, bases indurate 1/3–3/4, margins hyaline, scarious, erose distally, sparsely ciliolate distally, green zones lanceolate, outer often foliaceous distally, apices acute to long-acuminate, ± spreading, faces glabrous. |
Heads | in elongate, loosely racemiform arrays, branches ascending, heads single at ends of primary branches or long pedicels. |
Cypselae | reddish tan, obovoid, compressed, 1.5–2.8 mm, 4–5-nerved, faces strigillose; pappi yellowish, 7–8 mm. |
2n | = 80. |
Symphyotrichum anticostense |
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Phenology | Flowering Aug–Sep. |
Habitat | Calcareous, gravelly shores of rivers, lakeshore limestone pavements |
Elevation | 0–100 m (0–300 ft) |
Distribution |
ME; NB; QC
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Discussion | Of conservation concern. Symphyotrichum anticostense is known from disjunct areas: western Lake St. John, southern Anticosti Island, southern streams of the Gaspé Peninsula (Quebec), Restigouche River (Quebec–New Brunswick), and St. John (New Brunswick) and Aroostook (Maine; A. Haines 2000) rivers. It is an allopolyploid derivative of the cross between the calcareous fen species S. boreale and the widespread shore species S. novi-belgii (J. Labrecque and L. Brouillet 1990). It hybridizes with S. novi-belgii. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 529. |
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum |
Sibling taxa | |
Synonyms | Aster anticostensis, Aster gaspensis, Aster hesperius var. gaspensis |
Name authority | (Fernald) G. L. Nesom: Phytologia 77: 275. (1995) |
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