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

eastern silver American-aster, eastern silver aster, eastern silvery aster

Habit Perennials, 40–120(–200) cm, cespitose; short-rhizomatous or with stout, branched caudices. Perennials, 30–80 cm, cespitose; with cormoid, woody caudices.
Stems

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

1–10+, ascending to erect (light to dark brown), glabrous or densely canescent distally.

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.

(green to graysih) soft to firm;

basal withering by flowering, sessile, blades (1–3-nerved) elliptic-lanceolate, 10–43 × 5–15 mm, bases attenuate, margins usually entire, rarely remotely serrate, piloso-ciliate, apices acute to obtuse, faces silvery silky-pilose to sparsely pilose;

proximal cauline withering by flowering, sessile, blades oblanceolate, 20–35 × 5–15 mm, bases rounded, subclasping, margins entire, scabrous to silky-pilose, apices acute to obtuse, cuspidate mucronate, faces ± densely silky;

distal sessile, blades usually oblong to lanceolate, rarely ovate, 9–15 × 1.8–5 mm, reduced distally, bases cuneate, margins entire, apices acute, mucronate, faces ± densely silky or sparsely strigose, sometimes glabrate (var. devestitum).

Peduncles

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

densely hairy, bracts becoming linear, grading into phyllaries.

Involucres

cylindric, (4–)4.5–6(–7) mm.

campanulate to narrowly campanulate, 5–7 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.

8–12;

corollas rose-purple, rarely white, laminae 4–9 × 1–1.5 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.

(9–)11–17(–21);

corollas pink turning purple, 4.5–6 mm, tubes shorter than narrowly funnelform throats (thinly puberulent), lobes triangular, 0.4–0.7 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 3–5 series, appressed, lanceolate-oblong, strongly unequal, bases (tan) ± indurate, margins scarious proximally, green distally, green zones restricted to apex, obscured by hair, apices usually acute, sometimes acuminate, usually mucronate, sometimes subspinulose, faces ± densely silky.

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 narrow, paniculiform (virgate) arrays (1–3(–5) per branch).

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.

obovoid, not compressed, 2.5–3.5 mm, 7–10-nerved, faces densely strigose;

pappi tan, (3.5–)4–6 mm.

2n

= 16.

Symphyotrichum urophyllum

Symphyotrichum concolor

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; DE; FL; GA; KY; LA; MA; MD; MS; NC; NJ; NY; RI; SC; TN; VA
[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 2 (2 in the flora).

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

Key
1. Distal cauline leaves and phyllaries moderately to densely silky; e United States
var. concolor
1. Distal cauline leaves and phyllaries glabrous or sparsely hispido-pilose; panhandle Florida
var. devestitum
Source FNA vol. 20, p. 506. FNA vol. 20, p. 492.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus
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. 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
Subordinate taxa
S. concolor var. concolor, S. concolor var. devestitum
Synonyms Aster urophyllus, Aster sagittifolius var. dissitiflorus Aster concolor, Lasallea concolor, Virgulus concolor
Name authority (Lindley ex de Candolle) G. L. Nesom: Phytologia 77: 294. (1995) (Linnaeus) G. L. Nesom: Phytologia 77: 278. (1995)
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