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perennial saltmarsh American-aster, perennial saltmarsh aster

aster du golfe du saint-laurent, Gulf Of St. Lawrence aster

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.

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.

Peduncles

0.6–4 (–6) cm, bracts 2–8, awl-shaped, grading into phyllaries.

glabrous, bracts linear.

Involucres

narrowly turbinate, 4.1–9.5(–11) mm.

campanulate, 5–8+mm.

Ray florets

10–25;

corollas white or pink, laminae (4.5–)5–8.5(–9.5) × 1.2–2 mm.

0.

Pistillate florets

14–47+ in 2–3+ series;

laminae 0 (corolla tubes 2–2.4 mm, shorter than style branches).

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.

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.

Heads

(1–)3–20(–40), in open, diffuse, paniculiform arrays, branches patent.

(disciform) in ± densely paniculiform arrays.

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.

2n

= 14.

Symphyotrichum tenuifolium

Symphyotrichum laurentianum

Phenology Flowering Aug–Sep.
Habitat Brackish sand and mud, intertidal salt marshes, moist dune slacks
Elevation 0 m (0 ft)
Distribution
from FNA
AL; CT; DE; FL; GA; LA; MA; MD; ME; MS; NC; NH; NJ; NY; RI; SC; TX; VA; West Indies
[WildflowerSearch map]
[BONAP county map]
from FNA
NB; PE; QC
[BONAP county map]
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.)

Key
1. Stems 1, rhizomes long; mid leaves (1.5–)3–6 mm wide; involucres 6–9.5(–11) mm; ray florets (12–)17–25; disc florets 25–45(–54), corollas (4–)4.7–6(–6.5) mm; cypselae 2.8–4(–4.5) mm; pappi 5–6.1 mm
var. tenuifolium
1. Stems 1–5+ (clustered), rhizomes short; mid leaves (1–)1.5–2.7 mm wide; involucres 4.1–5.3 mm; ray florets 10–16; disc florets (10–)13–23, corollas 3.4–4.6 mm; cypselae 1.5–2(–2.5) mm; pappi 3–4.4 mm
var. aphyllum
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
S. adnatum, S. anomalum, S. anticostense, S. ascendens, S. boreale, S. bracteolatum, S. campestre, S. chapmanii, S. chilense, S. ciliatum, S. ciliolatum, S. concolor, S. cordifolium, S. cusickii, S. defoliatum, S. depauperatum, S. drummondii, S. dumosum, S. elliottii, S. ericoides, S. eulae, S. falcatum, S. fendleri, S. firmum, S. foliaceum, S. fontinale, S. frondosum, S. georgianum, S. grandiflorum, S. greatae, S. hallii, S. hendersonii, S. jessicae, S. laeve, S. lanceolatum, S. lateriflorum, S. laurentianum, S. lentum, S. molle, S. nahanniense, S. novae-angliae, S. novi-belgii, S. oblongifolium, S. ontarionis, S. oolentangiense, S. parviceps, S. patens, S. phlogifolium, S. pilosum, S. plumosum, S. porteri, S. potosinum, S. praealtum, S. pratense, S. prenanthoides, S. priceae, S. puniceum, S. pygmaeum, S. racemosum, S. retroflexum, S. rhiannon, S. robynsianum, S. sericeum, S. shortii, S. simmondsii, S. spathulatum, S. subspicatum, S. subulatum, S. tradescantii, S. turbinellum, S. undulatum, S. urophyllum, S. walteri, S. welshii, S. yukonense, S. ×amethystinum
S. adnatum, S. anomalum, S. anticostense, S. ascendens, S. boreale, S. bracteolatum, S. campestre, S. chapmanii, S. chilense, S. ciliatum, S. ciliolatum, S. concolor, S. cordifolium, S. cusickii, S. defoliatum, S. depauperatum, S. drummondii, S. dumosum, S. elliottii, S. ericoides, S. eulae, S. falcatum, S. fendleri, S. firmum, S. foliaceum, S. fontinale, S. frondosum, S. georgianum, S. grandiflorum, S. greatae, S. hallii, S. hendersonii, S. jessicae, S. laeve, S. lanceolatum, S. lateriflorum, S. lentum, S. molle, S. nahanniense, S. novae-angliae, S. novi-belgii, S. oblongifolium, S. ontarionis, S. oolentangiense, S. parviceps, S. patens, S. phlogifolium, S. pilosum, S. plumosum, S. porteri, S. potosinum, S. praealtum, S. pratense, S. prenanthoides, S. priceae, S. puniceum, S. pygmaeum, S. racemosum, S. retroflexum, S. rhiannon, S. robynsianum, S. sericeum, S. shortii, S. simmondsii, S. spathulatum, S. subspicatum, S. subulatum, S. tenuifolium, S. tradescantii, S. turbinellum, S. undulatum, S. urophyllum, S. walteri, S. welshii, S. yukonense, S. ×amethystinum
Subordinate taxa
S. tenuifolium var. aphyllum, S. tenuifolium var. tenuifolium
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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