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aster éricoïde, heath American-aster, heath-leaf aster, little gray aster, rayless alkali aster, tuft white prairie aster, white heath aster

Cusick's American aster, Cusick's aster

Habit Perennials, 20–80(–100) cm, colonial or cespitose, eglandular; branched rhizomatous, or with ± cormoid, branched, woody caudices. Perennials, 40–100 cm, colonial or cespitose; long-rhizomatous.
Stems

1–3+, ascending to erect (grayish brown to brown), sparsely to densely hispido-strigose, sometimes glabrescent proximally.

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

Leaves

usually all except rameal withered by flowering, (light grayish green) firm apices ± white-spine-tipped (often with clusters of smaller leaves in axils);

basal sessile, blades (3-nerved) oblanceolate to oblong or spatulate, 10–50 × 10–25 mm, bases attenuate, margins usually entire, rarely remotely serrate, scabrous, apices rounded to obtuse, faces usually sparsely hairy, often glabrous;

proximal cauline sessile, blades (1- or 3-nerved) linear to lanceolate or oblong, 10–40(–60) × 1.5–4(–7) mm, reduced distally, bases cuneate, coarsely ciliate, margins entire, coarsely ciliate, apices acute or obtuse, faces moderately to densely strigose or hirsute;

distal sessile, blades oblong-ovate, 10–40 × 1.5–3.5 mm, abruptly reduced distally, bases cuneate, margins entire, apices acute, faces moderately to densely strigose.

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

basal often withering by flowering, petiolate, blades broadly elliptic to obovate, 5–200 × 10–35 mm, attenuate or cuneate, margins entire, apices acute;

proximalmost cauline sometimes withering by flowering, sessile, blades oblanceolate to obovate, 70–120 × 15–50 mm, bases strongly clasping, enlarged and usually narrowed distally, usually prominently auriculate, margins entire, apices acute;

distal sessile, blades lanceolate to broadly elliptic, 30–110 × 10–30 mm, bases truncate or auriculate, margins entire.

Peduncles

0.5–1(–2) cm or subsessile, densely hairy, bracts dense, linear to narrowly lanceolate, usually reflexed, sometime appressed to ascending, 1.5–5(–6) mm, densely hairy, grading into phyllaries.

sparsely to densely cinereous, bracts lanceolate.

Involucres

cylindric to campanulate, 2.5–4.5(–5) mm.

campanulate, 10–20 mm.

Ray florets

(8–)10–18(–20);

corollas usually white, rarely pink or bluish, laminae 6–12(–20) × 0.7–1.2 mm.

25–55;

corollas violet, laminae 10–18 × 1–2 mm.

Disc florets

6–12(–20);

corollas yellow becoming brown, 2.5–4 mm, throats narrowly funnelform, lobes triangular, 0.5–0.6 mm, glabrous.

60–150+;

corollas yellow, 2.5–4 mm, lobes triangular, 0.4–0.5 mm.

Phyllaries

in 3–4 series, oblanceolate to ± spatulate, unequal, firm, bases (whitish to tan) ± indurate in proximal 1/2–2/3, margins hyaline, scabrous proximally, green zones diamond-shaped, in distal 1/2, apices spine-tipped, (outer) spreading to reflexed or squarrose, faces (outer) sparsely to densely hispid, scabroso-hirsute adaxially, (inner) glabrous.

in 4–5 series, broadly to narrowly lanceolate or oblanceolate (outer) to linear (inner), ± equal or outer slightly exceeding inner, bases outer foliaceous, inner scarious, margins scarious, entire or erose, green zones elliptic to lanceolate, apices acute, faces glabrous or finely hairy.

Heads

(1–200+) in paniculiform arrays, branches fastigiate or arrays often pyramidal, racemiform, secund, crowded.

borne singly or in often congested, paniculiform arrays, branches 20–30 cm.

Cypselae

deep purple turning brown, obovoid to oblong-obovoid, ± falcate, not compressed, 1.2–2 × 0.4–0.6 mm, 7–9-nerved (faint), faces sericeous or densely strigillose;

pappi whitish, 3–4 mm.

brown, cylindric to obovoid, not compressed, 3–3.5 mm, 3–6-nerved, faces hairy;

pappi white, 5–9(–11) mm.

2n

= 16, 32.

Symphyotrichum ericoides

Symphyotrichum cusickii

Phenology Flowering Jul–Aug.
Habitat Damp meadows in dry forests, often near springs and streams
Elevation 1000–1500 m (3300–4900 ft)
Distribution
from FNA
AR; AZ; CO; CT; DC; DE; IA; ID; IL; IN; KS; MA; MD; ME; MI; MN; MO; MS; MT; ND; NE; NJ; NM; NY; OH; OK; OR; PA; RI; SD; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NT; ON; QC; SK; n Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
ID; MT; OR; WA; AB
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

Symphyotrichum ericoides resembles S. pilosum var. pilosum, which has larger heads, longer rays, and phyllaries that are not spine-tipped, though the revolute margins can make them appear so. Two subspecies and four weakly separated varieties of S. ericoides were recognized by A. G. Jones (1978). Tetraploids of var. ericoides on the eastern prairies can be difficult to distinguish from S. falcatum. A number of aster cultivars are sold under the name “Aster ericoides.” These are all derived from European garden plants and are either cultivars of S. dumosum, S. lateriflorum, S. pilosum, or S. racemosum, or hybrids involving one of those species and another taxon. The misapplication of the epithet ericoides dates back to the nineteenth century and has persisted in the horticultural literature.

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

Symphyotrichum cusickii occurs principally in north-eastern Oregon, north-central Idaho, and adjacent western Montana.

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

Key
1. Plants colonial, rhizomatous, not cormoid; involucres cylindro-campanulate when fresh
var. ericoides
1. Plants cespitose, with cormoid caudices, not strongly rhizomatous; involucres broadly campanulate when fresh
var. pansum
Source FNA vol. 20, p. 494. FNA vol. 20, p. 532.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Occidentales
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. 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. 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. 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. turbinellum, S. undulatum, S. urophyllum, S. walteri, S. welshii, S. yukonense, S. ×amethystinum
Subordinate taxa
S. ericoides var. ericoides, S. ericoides var. pansum
Synonyms Aster ericoides, Lasallea ericoides, Virgulus ericoides Aster cusickii, Aster foliaceus var. cusickii
Name authority (Linnaeus) G. L. Nesom: Phytologia 77: 280. (1995) (A. Gray) G. L. Nesom: Phytologia 77: 278. (1995)
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