Symphyotrichum anticostense |
Symphyotrichum chapmanii |
|
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Anticosti American-aster, Anticosti aster, Anticosti Island aster, aster d'Anticosti |
savanna aster |
|
Habit | Perennials, 10–90 cm, colonial; long-rhizomatous. | Perennials, 30–80 cm, cespitose; rhizomes stout. |
Stems | 1, erect (straight, often reddish), glabrous. |
1–3+, erect (sometimes brown proximally, strict to straight), 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. |
green to dark green, firm, ± fleshy, margins entire, ciliate, apices acute, callous, faces sparsely strigillose; basal persistent or petiole bases marcescent, long-petiolate (to 15 cm; petioles sheathing, margins glabrous), blades linear to linear-lanceolate, 10–30 × 2–7 mm, bases cuneate to subattenuate, margins sparsely denticulate or entire, indurate-translucent; proximal cauline persistent, sessile or subpetiolate, blades linear, 42–105 × 1–3 mm, bases clasping, margins often revolute; distal sessile, blades usually linear, sometimes awl-shaped, 50–180 × 5–10 mm, strongly reduced distally, more abruptly so on array branches, bases subclasping to adnate for 1/2+ length, margins often revolute. |
Peduncles | 0.8–5.7 cm, slender, sparsely ot moderately pilosulous, bracts 3–5, linear-lanceolate, often crowded proximal to and surpassing heads. |
1–20+ cm, slender, glabrous, bracts 4–22, linear (awl-shaped), grading into phyllaries. |
Involucres | campanulate, 6–10 mm. |
cylindro-campanulate, 5.5–9 mm. |
Ray florets | 25–44; corollas usually pale purple or lilac, sometimes white, laminae 9.5–20 × 0.7–1.4 mm. |
8–23; corollas purple to blue-lavender, laminae (10–)14–15(–20) × 0.8–2.2 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. |
47–57; corollas pale yellow, 4.7–6.3 mm, throats funnelform to narrowly campanulate, lobes triangular, 0.5–0.7 mm (proximally sparsely pilose). |
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. |
in 4–5(–6) series, oblong-lanceolate (outer) to linear-lanceolate (innermost), bases indurate (at least inner), margins scarious, hyaline, purplish distally, ciliolate, green zones narrowly lanceolate, not evident, apices purplish, acute (outer) to acuminate (inner), sometimes mucronate (inner), faces sparsely villous. |
Heads | in elongate, loosely racemiform arrays, branches ascending, heads single at ends of primary branches or long pedicels. |
in open, usually corymbiform, sometimes ± paniculiform arrays, branches ascending, simple, slender, elongate. |
Cypselae | reddish tan, obovoid, compressed, 1.5–2.8 mm, 4–5-nerved, faces strigillose; pappi yellowish, 7–8 mm. |
tan to gray-brown (nerves stramineous), obovoid, compressed, 3.1–4.5 mm, 8–10(–14)-nerved, faces glabrous; pappi yellowish, 4.4–4.7 mm. |
2n | = 80. |
= 14. |
Symphyotrichum anticostense |
Symphyotrichum chapmanii |
|
Phenology | Flowering Aug–Sep. | Flowering Sep–Nov(–Dec). |
Habitat | Calcareous, gravelly shores of rivers, lakeshore limestone pavements | Wet savannas, pine flatwoods, bogs, and acid swamps |
Elevation | 0–100 m (0–300 ft) | 0–30 m (0–100 ft) |
Distribution |
ME; NB; QC
|
AL; FL |
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.) |
Of conservation concern. Symphyotrichum chapmanii is known from the Appalachicola Valley, northern Florida and adjacent southeast Alabama (where it is possibly extirpated), and is disjunct to St. Lucie County (Florida). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 529. | FNA vol. 20, p. 478. |
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | Asteraceae > tribe Astereae > Symphyotrichum > subg. Chapmaniani |
Sibling taxa | ||
Synonyms | Aster anticostensis, Aster gaspensis, Aster hesperius var. gaspensis | Aster chapmanii, Eurybia chapmanii, Heleastrum chapmanii |
Name authority | (Fernald) G. L. Nesom: Phytologia 77: 275. (1995) | (Torrey & A. Gray) Semple & Brouillet: in J. C. Semple et al., Cult. Native Asters Ontario, 133. (2002) |
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