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western aster, western mountain aster

prairie aster, smooth violet prairie aster, turbinate aster

Habit Perennials, 20–80 cm, colonial; long-rhizomatous. Perennials, 30–100 cm, cespitose; with thick, branched, woody caudices.
Stems

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

1–5+, erect, straight (stout, brittle), glabrous or sparsely hirtellous in lines.

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.

(paler green or bluish green abaxially) firm, margins scabrous, apices mucronate, faces glabrous, abaxial raised midribs scabrous to glabrate;

basal withering by flowering, subpetiolate to shortly petiolate (petioles winged, sheathing, coarsely ciliate), blades oblanceolate to oblong-oblanceolate, 45–65 × 5–8 mm, bases cuneate, margins shallowly crenate, strigoso-ciliate, apices acute, obtuse or rounded;

proximal cauline withering by flowering, subpetiolate or sessile, blades elliptic-lanceolate to linear-oblanceolate or -lanceolate, 40–120 × 5–20 mm, reduced distally, bases cuneate to slightly attenuate or rounded, slightly clasping, margins serrulate-crenate or entire, apices acute to acuminate;

distal sessile, blades oblanceolate or elliptic-lanceolate to linear-lanceolate or linear-oblong, (10–)15–100 × 1–5 mm, gradually reduced distally (more strongly so on branches), bases cuneate or rounded, margins entire, apices acuminate.

Peduncles

sparsely hairy, bracts 0–3+.

long, thin, (1–)4–10(–25) cm, branches to 10 cm, bracts 8–15, regularly spaced but becoming crowded distally, appressed or ascending, linear-oblong to subulate, 1.5–4 mm, grading into phyllaries, mucronulate.

Involucres

campanulate, 5–10 mm.

turbinate to cylindro-campanulate, 7–12 mm.

Ray florets

15–40;

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

14–20;

corollas light blue to lavender or purple, laminae 12–20 × (1–)1.5–2.8 mm.

Disc florets

30-80(–100);

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

15–20+;

corollas yellow turning purple, (4.5–)5–7 mm, tubes slightly shorter than narrowly funnelform throats, lobes triangular, 0.5–1 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 6–9 series, appressed or ± spreading, shortly oblong-lanceolate to subulate (outer) to linear-oblong or linear (inner), strongly unequal, bases indurate 1/2–5/6, abaxially rounded, margins scarious, erose, hyaline, sparsely ciliolate distally, green zones oblanceolate to rhombic-oblanceolate, in distal 1/6–1/2, apices acute (outer) to obtuse or rounded (inner), often callous-mucronulate, faces glabrous.

Heads

in corymbiform to paniculiform arrays, branches usually few.

in open, broad, much ramified, paniculiform arrays, branches ascending to arching, thin, brittle, remotely leafy, rarely sessile.

Cypselae

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

pappi whitish, 5–7 mm.

yellow-tan or light brown to gray, obovoid, ± compressed, (1.8–)2–2.8 mm, 2–4-nerved, faces minutely strigillose;

pappi whitish to reddish brown, 4.5–6.4 mm.

2n

= 96.

Symphyotrichum spathulatum

Symphyotrichum turbinellum

Phenology Flowering Aug–Oct.
Habitat Open, dry, acidic (chert, sandstone, or granite), rocky or loamy soils, woods and glades on upland slopes and ridges in soils associated with or on leached soils above bluffs, pastures, roadsides
Elevation 60–900 m (200–3000 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
AR; IA; IL; KS; LA; MO; NE; OK
[WildflowerSearch map]
[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.)

Symphyotrichum turbinellum is mostly Ozarkian.

(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. 530.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Occidentales Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum
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. 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. tenuifolium, S. tradescantii, 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 turbinellus
Name authority (Lindley) G. L. Nesom: Phytologia 77: 291. (1995) (Lindley) G. L. Nesom: Phytologia 77: 293. (1995)
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