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arrow-leaf American-aster, white arrowleaf aster, white arrowleaf or arrowleaf aster

aster lancéolé, lance-leaf American-aster, lance-leaf aster, lance-leaf or panicle or white panicle aster, marsh aster, panicle aster, tall white aster, western willow aster, white-panicle aster

Habit Perennials, 40–120(–200) cm, cespitose; short-rhizomatous or with stout, branched caudices. Perennials, 30–150(–200) cm, colonial; long-rhizomatous (rhizomes usually white, thick, contorted).
Stems

1–5+, erect (straight to slightly flexuous, brittle, sometimes stout), proximally glabrous or glabrate, distally sparsely pilose.

1, erect (straight, stout), glabrous or hairy.

Leaves

thin, margins usually shallowly, sometimes deeply serrate, rarely entire (distal), (piloso- to strigoso-)ciliate to scabrous (distal), apices mucronate, abaxial faces moderately pilose, ± densely so on midveins, adaxial glabrate to sparsely pilose or scabrous;

basal usually withering by flowering, sometimes persistent, long-petiolate (5–15 cm, petioles not or narrowly winged, sheathing), blades ovate to lance-ovate or lanceolate, 25–120 × 15–50 mm, bases usually shallowly, sometimes deeply, cordate to truncate or rounded, apices acute, sometimes rounded;

proximal cauline sometimes deciduous at flowering, winged-petiolate (petioles distally usually broader-winged, clasping), blades ovate to lanceolate, 50–120 × 20–50 mm, gradually reduced distally, bases usually truncate or rounded to attenuate, sometimes cordate, apices usually acute or acuminate, sometimes nearly caudate;

distal ± shortly winged-petiolate or sessile, blades lance-ovate or lanceolate to linear-lanceolate, 10–100 × 1–25 mm, reduced distally, bases attenuate to cuneate, margins entire to subentire, scabrous, apices acuminate to subcaudate.

thin, scabrous, apices mucronate, abaxial faces glabrous (vein areoles indistinct, elongate), adaxial glabrous or sparsely scabrous (var. hesperium);

basal withering by flowering, petiolate to subpetiolate (petioles winged, ciliate, bases dilated, sheathing), blades elliptic-oblanceolate or obovate to suborbiculate, 10–80 × 5–20 mm, cuneate to attenuate, margins crenate-serrate, apices acute to obtuse or rounded;

proximal cauline withering by flowering, sessile or subsessile, blades lance-ovate or oblanceolate to linear-lanceolate, (40–)50–150 × (3–)10–20(–35) mm, progressively reduced distally, bases cuneate, ± decurrent, margins serrate, apices acute to acuminate;

distal sessile, blades oblanceolate to linear, 30–100(–140) mm, only slightly reduced distally, bases cuneate, margins entire.

Peduncles

0.3–2 cm, sparsely pilosulous to glabrate, bracts many, ascending, linear to subulate, 2–4 mm, grading into phyllaries.

0.5–5 cm, ± pilose, bracts 1–3(–5), linear-oblanceolate to -lanceolate, foliaceous, ciliate.

Involucres

cylindric, (4–)4.5–6(–7) mm.

campanulate to cylindric, 3–8 mm.

Ray florets

8–15(–20);

corollas mostly white to pale pink or lilac or light blue, laminae 4.5–8(–10) × 0.8–1.5 mm.

16–50;

corollas white to pinkish or pale blue-violet, laminae 3–10(–14) × 0.5–1.3 mm.

Disc florets

(8–)10–15(–20);

corollas whitish to cream becoming pink, (3.5–)4–5 mm, tubes shorter than funnelform throats (with hairs), lobes lanceolate, 0.4–0.7 mm.

(13–)20–40(–52);

corollas yellow becoming purple, 2.8–5.8 mm, tubes shorter than funnelform throats, lobes sometimes ± spreading, triangular, 0.4–1.2 mm.

Phyllaries

in 4–6 series, appressed or recurved-spreading, subulate (outer) to linear-lanceolate (inner), unequal, bases indurate 1/3–1/2+, margins scarious, hyaline, erose, sparsely ciliolate (mostly distally), green zones linear-lanceolate (outer) to linear (inner), apices long-acuminate to caudate, recurved, hyaline-mucronate to aristate, tips often purple, faces glabrous.

in (3–)4–6 series, appressed or slightly spreading, linear-lanceolate to linear (innermost), sometimes slightly dilated distally, ± strongly unequal to subequal (var. hesperium), bases indurate 1/4–1/2, margins scarious, erose, hyaline, sparsely ciliolate, green zones lanceolate to linear-lanceolate, outer sometimes foliaceous (particularly var. hesperium), apices acute to acuminate (outer) or acuminate to caudate (inner), mostly mucronulate, abaxial faces glabrous, adaxial sparsely strigillose.

Heads

(crowded) in dense, elongate, paniculiform arrays, branches stiffly ascending to erect (sometimes arched when long, peduncles then often secund), usually racemiform, sometimes paniculiform, leafy.

in ample or diffuse to narrow, elongate, leafy, paniculiform arrays, branches ± ascending, rarely secund, branch leaves often longer than pedicels.

Cypselae

tan to brown or dull purple (nerves stramineous), obovoid, ± compressed, 1.8–2.5 mm, 4–6-nerved, faces glabrous or glabrate or very sparsely strigillose;

pappi white or rose-tinged, 3–4 mm.

gray or tan, obovoid, ± compressed, 1.5–2 mm, 4–5-nerved, faces sparsely strigillose;

pappi white to sordid or tawny, 5.5–6 mm.

2n

= 16.

Symphyotrichum urophyllum

Symphyotrichum lanceolatum

Phenology Flowering Aug–Oct.
Habitat Open, dry or mesic, sandy or loamy, sometimes rocky soils, limestone pavements, glades, ravines, open oak, sassafras, aspen, or pine woods, edges of woods, moist or dry, rocky bluffs, savanna, wooded banks, stabilized dunes, fields, roadsides, hedgerows, railroads
Elevation 40–300+ m (100–1000+ ft)
Distribution
from FNA
AL; AR; FL; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NJ; NY; OH; OK; PA; SC; TN; VA; VT; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; AZ; CA; CO; CT; DC; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK [Introduced in Europe]
[WildflowerSearch map]
[BONAP county map]
Discussion

The name Aster sagittifolius Wedemeyer ex Willdenow has been misapplied to this taxon; our interpretation of the type of this entity concords with that of A. G. Jones (1980), i.e., that it is conspecific with the type of Symphyotrichum cordifolium or a garden hybrid involving the latter. Aster sagittifolius forma hirtellus (Lindley) Shinners is not recognized here.

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

Varieties 5 (5 in the flora).

Varieties of Symphyotrichum lanceolatum are sometimes grouped into two subspecies: subsp. hesperium (var. hesperium) and subsp. lanceolatum (the other four varieties). J. C. Semple and J. G. Chmielewski (1987) provided maps of the five taxa. The ranges of var. hesperium and var. lanceolatum overlap in the prairies and in the boreal zone from Alberta to the Clay Belt of northern Ontario. The ranges of the other three varieties do not overlap with that of var. hesperium, but they all overlap each other and with var. lanceolatum in the Midwest. The ecology and cytogeography of the species were summarized by Chmielewski and Semple (2001). The name Aster tradescantii has sometimes been misapplied to this species.

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

Key
1. Outer phyllaries 2/3 + length of inner ones; heads usually subtended by large foliaceous bracts; cordilleras and prairies (subsp. hesperium)
var. hesperium
1. Outer phyllaries 1/3 – 2/3 length of inner ones; heads not usually subtended by large foliaceous bracts; prairies eastwards (subsp. lanceolatum)
→ 2
2. Stems stout, moderately to densely short-woolly from bases; Great Lakes region to se Manitoba
var. hirsuticaule
2. Stems stout to slender, glabrous or at most hairy in lines at bases
→ 3
3. Heads congested on lateral branches of arrays; involucres 3–4 mm; midwestern United States, s Ontario, s Quebec
var. interior
3. Heads not congested or congested only distally on lateral branches of arrays; involucres 3.6–5.6 mm (mostly longer than 4 mm)
→ 4
4. Leaves broadly oblanceolate, not much reduced in arrays; involucres usually 4–5.5 mm; rays white
var. latifolium
4. Leaves linear to oblanceolate, reduced in arrays; involucres 3.5–5(–6) mm; rays white to purplish
var. lanceolatum
Source FNA vol. 20, p. 506. FNA vol. 20.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum 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. spathulatum, S. subspicatum, S. subulatum, S. tenuifolium, S. tradescantii, S. turbinellum, S. undulatum, 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. 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. lanceolatum var. hesperium, S. lanceolatum var. hirsuticaule, S. lanceolatum var. interior, S. lanceolatum var. lanceolatum, S. lanceolatum var. latifolium
Synonyms Aster urophyllus, Aster sagittifolius var. dissitiflorus Aster lanceolatus
Name authority (Lindley ex de Candolle) G. L. Nesom: Phytologia 77: 294. (1995) (Willdenow) G. L. Nesom: Phytologia 77: 284. (1995)
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