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western aster, western mountain aster

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

Habit Perennials, 20–80 cm, colonial; long-rhizomatous. Annuals, 1–13+ cm.
Stems

1–5+, ascending to erect, glabrous or sparsely puberulent.

1, decumbent to erect (straight), glabrous.

Leaves

thin, margins entire, apices acute, faces glabrous or sparsely puberulent;

basal persistent, petiolate, blades narrowly elliptic to obovate, 50–150 × 3–15 mm, attenuate, margins entire;

proximal cauline sessile or subpetiolate, blades linear to narrowly elliptic, 50–150 × 2–15 mm, bases attenuate or cuneate;

distal sessile, blades 30–60 × 2–10 mm, reduced distally, bases cuneate to rounded.

± 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

sparsely hairy, bracts 0–3+.

glabrous, bracts linear.

Involucres

campanulate, 5–10 mm.

campanulate, 5–8+mm.

Ray florets

15–40;

corollas violet, laminae 9–15 × 1–2 mm.

0.

Pistillate florets

14–47+ in 2–3+ series;

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

Disc florets

30-80(–100);

corollas yellow, sometimes becoming reddish, 4.5–6 mm, lobes triangular, 0.5–1 mm.

5–8+;

corollas yellow, 3.1–3.9 mm, lobes deltate to triangular, 0.2–0.3 mm.

Phyllaries

in 3–5 series, narrowly oblong or linear (outer) to linear (inner), unequal, bases indurate, margins entire, green zones elliptic to lanceolate, apices usually acute, sometimes obtuse, faces glabrous or ± puberulent.

in 3–4 series, lanceolate, subequal, bases scarious, margins eciliate, green zones foliaceous (outer), apices obtuse, faces glabrous.

Heads

in corymbiform to paniculiform arrays, branches usually few.

(disciform) in ± densely paniculiform arrays.

Cypselae

brown, cylindric to obovoid, not compressed, 2.5–3.5 mm, ± 4-nerved, faces hairy;

pappi whitish, 5–7 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 spathulatum

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
CA; CO; ID; MT; NM; NV; OR; UT; WA; WY; AB; BC; NT; nw Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
NB; PE; QC
[BONAP county map]
Discussion

Varieties 3 (3 in the flora).

Symphyotrichum spathulatum is a variable species, widespread in montane regions of western North America. It hybridizes with S. bracteolatum, S. foliaceum, and S. hendersonii.

(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. Leaves linear
var. yosemitanum
1. Leaves narrowly elliptic to oblanceolate
→ 2
2. Plants 40–80 cm; heads usually 10–50
var. intermedium
2. Plants 20–50(–60) cm; head usually 3–10
var. spathulatum
Source FNA vol. 20, p. 534. FNA vol. 20, p. 500.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Occidentales 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. subspicatum, S. subulatum, S. tenuifolium, 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. spathulatum var. intermedium, S. spathulatum var. spathulatum, S. spathulatum var. yosemitanum
Synonyms Aster spathulatus Aster laurentianus, Aster laurentianus var. contiguus, Aster laurentianus var. magdalenensis
Name authority (Lindley) G. L. Nesom: Phytologia 77: 291. (1995) (Fernald) G. L. Nesom: Phytologia 77: 286. (1995)
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