Symphyotrichum tenuifolium |
Symphyotrichum laurentianum |
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perennial saltmarsh American-aster, perennial saltmarsh aster |
aster du golfe du saint-laurent, Gulf Of St. Lawrence aster |
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Habit | Perennials, (20–)40–60(–100) cm, colonial or cespitose; rhizoma-tous. | Annuals, 1–13+ cm. | ||||
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, decumbent to erect (straight), 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. |
± fleshy, margins entire, eciliate, apices obtuse, faces glabrous; basal deciduous at bolting, petiolate, blades oblanceolate 44–50 × 5–7 mm [cult.], bases attenuate; proximal cauline and some distal withering by flowering; cauline sessile, blades linear-lanceolate to spatulate, 15–55 × 1–4 mm, reduced distally, bases cuneate; distal sessile, blades linear-lanceolate to spatulate. |
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Peduncles | 0.6–4 (–6) cm, bracts 2–8, awl-shaped, grading into phyllaries. |
glabrous, bracts linear. |
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Involucres | narrowly turbinate, 4.1–9.5(–11) mm. |
campanulate, 5–8+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. |
0. |
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Pistillate florets | 14–47+ in 2–3+ series; laminae 0 (corolla tubes 2–2.4 mm, shorter than style branches). |
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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. |
5–8+; corollas yellow, 3.1–3.9 mm, lobes deltate to triangular, 0.2–0.3 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 3–4 series, lanceolate, subequal, bases scarious, margins eciliate, green zones foliaceous (outer), apices obtuse, faces glabrous. |
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Heads | (1–)3–20(–40), in open, diffuse, paniculiform arrays, branches patent. |
(disciform) in ± densely paniculiform arrays. |
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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, obovoid, ± compressed, 2.8–2.9 mm, 2–4-nerved, faces strigillose; pappi white to yellowish white, 4.8–5.2 mm. |
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2n | = 14. |
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Symphyotrichum tenuifolium |
Symphyotrichum laurentianum |
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Phenology | Flowering Aug–Sep. | |||||
Habitat | Brackish sand and mud, intertidal salt marshes, moist dune slacks | |||||
Elevation | 0 m (0 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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NB; PE; QC |
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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.) |
Of conservation concern. Symphyotrichum laurentianum is known only from the southern shores of the Gulf of St. Lawrence. (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. 500. | ||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Conyzopsis | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Aster tenuifolius | Aster laurentianus, Aster laurentianus var. contiguus, Aster laurentianus var. magdalenensis | ||||
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 293. (1995) | (Fernald) G. L. Nesom: Phytologia 77: 286. (1995) | ||||
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