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intermountain aster, long-leaf aster, long-leaf or intermountain or western aster, western American aster, western aster

Short's aster

Habit Perennials 20–60 cm, colonial; long-rhizomatous. Perennials, 30–150 cm, cespitose; short-rhizomatous or with ± woody caudices.
Stems

1–5+, ascending to erect, densely and uniformly strigose, especially distally.

1–5+, ascending to erect (straight, sometimes stout), proximally glabrous, distally ± densely hirtellous.

Leaves

(grayish green) thin to firm, margins entire, apices acute, faces glabrous or strigose;

basal usually persistent, petiolate, blades oblanceolate, 50–150 × 5–12(–15) mm, bases attenuate or cuneate, margins entire, apices usually acute;

proximal cauline sessile or subpetiolate, blades oblong to narrowly obovate, 50–120 × 5–12 mm, bases attenuate or cuneate;

distal sessile, blades 30–70 × 4–10 mm, reduced distally, bases cuneate to ± rounded.

thin, margins often slightly revolute, scabrous, apices mucronate or mucronulate, abaxial faces sparsely to moderately hispid, especially along veins, adaxial glabrous (midveins scabrous, veins marked) to strigoso-hispid (basal);

basal withering by flowering (new winter rosette sometimes developing), petiolate (petioles 1–2 times as long as blades, sometimes narrowly winged, sheathing, densely pilose or hirsute), blades ovate to lance-ovate, 10–60 × 10–35 mm, deeply to shallowly cordate or rounded, margins crenate or crenate-serrate, apices obtuse to acute;

proximal cauline mostly persistent, narrowly petiolate (petioles slender, progressively reduced distally, bases at most slightly clasping), blades ovate to lanceolate, 50–150 × 20–60(–70) mm, progressively reduced distally, bases shallowly cordate to subcordate, truncate, or rounded, sometimes oblique, margins entire, scabrous or shallowly crenate-serrate (proximal), apices acute to acuminate;

distal short-petiolate (petioles sometimes narrowly winged, sometimes slightly clasping) or sessile (distalmost, rameal), blades ovate to lanceolate (rameal lance-linear to linear, sharply smaller), 8–80 × 1–40 mm, gradually reduced distally, bases rounded to cuneate or attenuate, margins entire to subentire, apices acute to acuminate.

Peduncles

moderately to densely strigose, bracts 1–4, linear to oblanceolate.

0.2–3(–5) cm, densely hirtellous, bracts 3–10+, ovate or lanceolate to subulate, grading into phyllaries.

Involucres

campanulate, 4–7 mm.

cylindro-campanulate, 4–6 mm.

Ray florets

(10–)15–40;

corollas violet, laminae 8–13 × 1–1.5 mm.

13–15(–20);

corollas usually blue or purple-blue, seldom pinkish or white, laminae (10–)11–16 × 1.3–3.1 mm.

Disc florets

25–65(–80);

corollas yellow, sometimes purple-tinged, 4–6 mm, lobes triangular, 0.4–0.8 mm.

16–23(–28?);

corollas light yellow becoming reddish purple, 4.6–7 mm, tubes shorter than funnelform throats, lobes lanceolate, 0.4–1.1 mm.

Phyllaries

in 3–5 series, narrowly oblanceolate or linear (outer) to linear (inner), unequal, bases indurate, margins entire, green zones obovate to elliptic, apices obtuse, faces densely strigose.

in 4–5(–6) series, appressed, lanceolate or oblong-lanceolate (outer) to linear-lanceolate or linear (inner), strongly unequal, bases indurate 1/2–5/6, margins scarious, erose, hyaline, ciliolate, green zones lanceolate to diamond-shaped (midveins below green zone sometimes inflated and brownish), apices acute to acuminate, often involute, mucronulate, faces strigilloso-hirsutulous.

Heads

in paniculiform arrays, branches ascending.

usually in open, diffuse to narrow, paniculiform arrays, sometimes racemiform, branches widely spreading, usually divaricate to arching, sometimes ascending, sometimes ± secund, abundantly leafy.

Cypselae

brown, cylindric to obovoid, not compressed, 2–3.5 mm, 3–5-nerved, faces hairy;

pappi whitish, 4–7 mm.

dull purple or brown, oblong-obovoid, compressed, 2.5–3.7 mm, 4–7-nerved, faces glabrous;

pappi reddish brown, tawny, or rose-tinged, 4–6.2 mm.

2n

= 26, 36, 52.

= 16, 32.

Symphyotrichum ascendens

Symphyotrichum shortii

Phenology Flowering Jul–Aug. Flowering Aug–Oct.
Habitat Meadows, grasslands, damp areas in sagebrush steppe and Ponderosa pine woodlands Open, often thin, rocky, well-drained soils, oak-hickory woods, edges of woods, thickets, calcareous hammocks, wooded stream banks or cliffs, roadsides
Elevation 500–3200 m (1600–10500 ft) 100–500 m (300–1600 ft)
Distribution
from FNA
AZ; CA; CO; ID; MT; ND; NM; NV; OR; UT; WA; WY; AB; BC; SK
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; FL; GA; IA; IL; IN; KY; MD; MI; MN; MS; NC; PA; TN; VA; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
Discussion

Symphyotrichum ascendens is widely distributed in the Great Basin. It is an allopolyploid derived from the hybrid between S. spathulatum (x = 8) and S. falcatum (x = 5). Chromosome numbers differ markedly in their geographic distribution, 2n = 26 prevailing in the southwestern part of the range, and 2n = 52 in the northeastern part (G. A. Allen 1985) Backcrosses to both parental species or hybrids with related taxa are sometimes seen where the ranges overlap.

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

Symphyotrichum shortii is of conservation concern along the whole periphery of its range, notably in Canada; there is a report from the District of Columbia but the species is not established there. Aster shortii Lindley forma gronemannii Benke is a roseate phenotype, and forma candidus Benke a white one, forma shortii being the normal blue or purple one. They are not recognized here.

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

Source FNA vol. 20, p. 538. FNA vol. 20, p. 505.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Ascendentes Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum
Sibling taxa
S. adnatum, S. anomalum, S. anticostense, 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. 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. 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
Synonyms Aster ascendens, Aster chilensis subsp. ascendens Aster shortii, Aster camptosorus
Name authority (Lindley) G. L. Nesom: Phytologia 77: 276. (1995) (Lindley) G. L. Nesom: Phytologia 77: 291. (1995)
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