The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Photo is of parent taxon

larger western mountain aster, western mountain aster

western aster, western mountain aster

Habit Plants 40–80 cm. Perennials, 20–80 cm, colonial; long-rhizomatous.
Stems

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

Leaves

narrowly elliptic to oblanceolate.

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.

Peduncles

sparsely hairy, bracts 0–3+.

Involucres

campanulate, 5–10 mm.

Ray florets

15–40;

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

Disc florets

30-80(–100);

corollas yellow, sometimes becoming reddish, 4.5–6 mm, 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.

Heads

10–50(–75).

in corymbiform to paniculiform arrays, branches usually few.

Cypselae

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

pappi whitish, 5–7 mm.

64

.

2n

= 32, 48.

Symphyotrichum spathulatum var. intermedium

Symphyotrichum spathulatum

Phenology Flowering Jul–Aug.
Habitat Grasslands and montane meadows, open coniferous forests
Elevation 1200–2000 m (3900–6600 ft)
Distribution
from FNA
CA; ID; NV; OR; WA; BC
[BONAP county map]
from FNA
CA; CO; ID; MT; NM; NV; OR; UT; WA; WY; AB; BC; NT; nw Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Variety intermedium is found mainly in the northern part of the species range and is only occasional in California and Nevada.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

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.)

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. 535. FNA vol. 20, p. 534.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Occidentales > Symphyotrichum spathulatum Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Occidentales
Sibling taxa
S. spathulatum var. spathulatum, S. spathulatum var. yosemitanum
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
Subordinate taxa
S. spathulatum var. intermedium, S. spathulatum var. spathulatum, S. spathulatum var. yosemitanum
Synonyms Aster occidentalis var. intermedius, Aster vallicola Aster spathulatus
Name authority (A. Gray) G. L. Nesom: Phytologia 77: 292. (1995) (Lindley) G. L. Nesom: Phytologia 77: 291. (1995)
Web links