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western aster, western mountain aster

aster latériflore, calico American-aster, calico aster, calico or one-side or white woodland or starved aster

Habit Perennials, 20–80 cm, colonial; long-rhizomatous. Perennials, 20–120(–150) cm, cespitose; with short, woody, branched caudices, or short-rhizomatous.
Stems

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

1–5+, ascending to erect (± arching, slender, brittle), ± densely pilose or villous to glabrate or glabrous (particularly proximally).

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.

thin, membranous, margins serrate to serrulate, scabridulous, apices acute to acuminate, sometimes caudate, mucronulate, abaxial faces glabrous, midveins usually ± densely pilose to glabrate, rarely glabrous, adaxial scabrous (short-strigose) to glabrate;

basal usually withering by flowering, sometimes persisting (new vernal rosettes often developing at flowering), petiolate to subpetiolate (petioles narrowly to ± broadly winged, ciliate, bases ± sheathing), blades oblanceolate, lance-ovate or ovate to spatulate or suborbiculate, 5–35 × 7–25 mm, abruptly attenuate, margins crenate-serrate, apices obtuse to rounded or acute;

proximal cauline mostly withering by flowering, sessile or subpetiolate (petioles broadly winged), blades usually ovate or elliptic to elliptic-oblanceolate or lanceolate, rarely linear-lanceolate, (30–)50–100(–150) × (2–)10–20(–35) mm, greatly reduced distally, bases attenuate to cuneate;

distal sessile, blades ovate, lance-ovate, lance-elliptic, or oblanceolate to lance-linear or linear, 10–150 × 1–30 mm, progressively reduced distally, branch leaves abruptly smaller, bases cuneate, margins sometimes entire.

Peduncles

sparsely hairy, bracts 0–3+.

Involucres

campanulate, 5–10 mm.

cylindro-campanulate, (3.5–)4–6(–7) mm.

Ray florets

15–40;

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

8–15(–23);

corollas white, rarely pinkish or purplish, laminae (3–)4–5(–8) × 0.9–1.2 mm.

Disc florets

30-80(–100);

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

8–16(–20);

corollas cream to light yellow turning pink or reddish purple, (2.5–)3–5 mm, tubes shorter than funnelform-campanulate throats, lobes strongly reflexed, lanceolate, 0.9–1.7 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(–6) series, appressed or slightly spreading, oblong-lanceolate or -oblanceoalte (outer) to linear (inner), unequal, bases indurate 1/3–2/3, margins scarious, erose, hyaline or sometimes reddish, ± ciliolate, green zones lanceolate to ± diamond-shaped, apices (outer) acute, callus-pointed, (mid) acute to acuminate, or obtuse, sometimes purplish, abaxial faces glabrous (outer), mid sparsely puberulent.

Heads

in corymbiform to paniculiform arrays, branches usually few.

in ample, open, diffuse, ± pyramidal, paniculiform arrays, branches divaricate to long-arching or ± ascending, slender, wiry, secund; usually sessile, sometimes peduncles 0.1–1 cm+, ± pilose, bracts 1–7, linear or subulate to oblong-lanceolate, foliaceous, grading into phyllaries.

Cypselae

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

pappi whitish, 5–7 mm.

gray or tan, oblong-obovoid, sometimes ± compressed, (1.3–)1.8–2.2 mm, 3–5-nerved, faces sparsely strigillose;

pappi white to pinkish, 3–4 mm.

2n

= 16, 32, 48.

Symphyotrichum spathulatum

Symphyotrichum lateriflorum

Phenology Flowering Aug–Oct.
Habitat Relatively shaded habitats, dry to humid soils, usually deciduous woodlands (beech–maple, oak–hickory, mixed hardwoods), sometimes conifer woods, sometimes swamp forests (conifer or dediduous), edges of woods, meadows, usually rocky or sandy stream and pond shores, roadsides
Elevation 0–400 m (0–1300 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
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; MB; NB; NS; ON; PE; QC
[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 lateriflorum has been reported in British Columbia as an ephemeral that did not persist. G. L. Nesom (1994b) and J. C. Semple et al. (2002) recognized several varieties within the complex: var. lateriflorum (syn. Aster vimineus Lamarck); var. angustifolium (Wiegand) G. L. Nesom (syn. A. lateriflorus var. angustifolius Wiegand); var. flagellare (Shinners) G. L. Nesom (syn. A. lateriflorus var. flagellaris Shinners, A. lateriflorus var. indutus Shinners); var. hirsuticaule (Lindley ex de Candolle) G. L. Nesom [syn. A. hirsuticaulis Lindley ex de Candolle, A. lateriflorus var. hirsuticaulis (Lindley ex de Candolle) Porter]; var. horizontale (Desfontaines) G. L. Nesom [syn. A. horizontalis Desfontaines, A. lateriflorus var. horizontalis (Desfontaines) Farwell]; var. spatelliforme (E. S. Burgess) G. L. Nesom [syn. A. spatelliformis E. S. Burgess, A. lateriflorus var. spatelliformis (E. S. Burgess) A. G. Jones]; and var. tenuipes (Wiegand) G. L. Nesom (syn. A. lateriflorus var. tenuipes Wiegand, A. acadiensis Shinners). Much genetic and phenotypic variation is encountered within the complex; a thorough study is needed before a coherent taxonomy can be achieved.

(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. 517.
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. 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. 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 Solidago lateriflora, Aster lateriflorus
Name authority (Lindley) G. L. Nesom: Phytologia 77: 291. (1995) (Linnaeus) Á. Löve & D. Löve: Taxon 31: 359. (1982)
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