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aster poilu, awl American-aster, frost aster, hairy aster, hairy white Oldfield aster, Oldfield or frost weed or white Oldfield or hairy or hairy white Oldfield aster, white heath aster

aster cordifolié, common blue wood aster, heart-leaf American-aster, heart-leaf aster, heartleaf or common blue wood aster

Habit Perennials cespitose, (5–)20–120(–150+) cm; with stout, branched caudices, sometimes long-rhizomatous. Perennials, 20–120 cm, colonial or cespitose; branched rhizomatous, or with branched caudices, becoming ± woody.
Stems

1–5+, ascending to erect (straight, stout), glabrate to hirsuto-hispid or pilose, sometimes glabrous or hairy in lines (var. pringlei).

1–5+, erect (straight to ± flexuous distally, often reddish, sometimes brown), usually glabrous, sometimes ± pilose, particularly distally.

Leaves

thin, margins ciliate, apices acute to acuminate, mucronate, faces glabrous or ± hirsute (particularly on abaxial midveins);

basal withering by flowering (new vernal rosettes developing at flowering), petiolate to subpetiolate (petioles winged, ciliate, bases sheathing), blades oblanceolate or obovate to spatulate, 10–60 × 5–15 mm, bases attenuate, margins sparsely crenate-serrate (mostly apically), apices obtuse to rounded;

proximal cauline usually deciduous at flowering (often with axillary clusters of small leaves), petiolate or subpetiolate to subsessile (petioles narrowly to broadly winged, clasping), blades elliptic-oblanceolate or -oblong to linear-lanceolate or -oblanceolate, 40–102 × 5–25 mm, progressively reduced distally, bases attenuate to cuneate, ± clasping, margins entire to serrate, softly ciliate, apices attenuate, hyaline-spinulose;

distal sessile, blades lance-oblong to linear-lanceolate to linear or linear-oblanceolate or linear-subulate, 10–100 × 1–8 mm, progressively reduced distally, branch leaves abruptly smaller, bases cuneate, margins entire or serrulate.

thin, margins serrate (often sharply, teeth acuminate, mucronulate) to serrate-crenate or subentire, strigose, apices acuminate to acute, mucronulate, abaxial faces glabrous or sparsely to densely strigose-pilose, often pilose on midveins, sometimes on other veins also, adaxial glabrous or sparsely to densely strigose, sometimes ± scabrous;

basal withering by flowering, new vernal rosettes often present, long-petiolate (petioles ± narrowly winged, bases dilated, sheathing, ciliate), blades ovate to elliptic or suborbiculate, (10–)35–150 × (10–)25–75 mm, bases usually deeply cordate, sometimes rounded, margins coarsely, often irregularly serrate, apices sometimes obtuse or rounded;

proximal cauline often withering by flowering, winged-petiolate (becoming shorter and more widely winged distally, petiole bases clasping), blades widely to narrowly ovate, 40–100(–140) × 20–40(–70) mm, reduced distally, bases ± deeply cordate to rounded, margins sharply serrate, apices acuminate;

distal usually sessile or subsessile, rarely short-petiolate, blades ovate to lanceolate, 5–105 × 2–45 mm, bases cordate or rounded to attenuate or cuneate, margins serrate or entire (distalmost), apices acuminate.

Peduncles

5–30(–50) mm, progressively shorter distally, glabrous or densely hispid, bracts 7–25+, appressed to ascending, sometimes ± spreading, linear to subulate, glabrate, ciliate or not, mucronate to apiculate, ± grading into phyllaries.

0.3–2 cm, ± pilose, bracts linear-oblanceolate or -lanceolate to linear, foliaceous, distally grading into phyllaries, margins sparsely ciliolate, glabrous.

Involucres

campanulate to cylindro-campanulate, (2.5–)3.5–5.1(–6.5) mm.

cylindro-campanulate to cylindric, (3–)4.5–5(–6) mm.

Ray florets

(10–)16–28(–38);

corollas usually white, rarely pinkish or bluish, laminae (4–)5.4–7.5(–11) × (0.4–)0.8–1.3(–1.7) mm.

(8–)10–16(–20);

corollas usually blue to purple, seldom whitish or pink, laminae (5–)6–8(–10) × 1.4–1.8 mm.

Disc florets

(13–)17–39(–67);

corollas light yellow becoming reddish purple or brown, (2.5–)3–4.1(–5.5) mm, tubes much shorter than narrowly funnelform throats, lobes lanceolate, (0.4–)0.6–0.8(–1) mm.

(8–)10–15(–20);

corollas cream-color or light yellow becoming purple, (3–)4–4.5(–5) mm, tubes slightly shorter than funnelform throats, lobes sometimes ± spreading, narrowly triangular to lanceolate, 0.6–0.9 mm.

Phyllaries

in 4–6 series, appressed or slightly spreading, oblong-lanceolate (outer) to linear (innermost) , unequal (rarely subequal), bases indurate 1/2–3/5, margins hyaline, scarious, erose, ± ciliolate distally, green zones lanceolate to lance-rhombic, apices acute or acuminate, involute, spinulose, faces glabrous or sparsely hirsutulous.

in (3–)4–6 series, linear-lanceolate to oblong-lanceolate, unequal, bases indurate 1/2–3/4, margins scarious, erose, hyaline, sparsely ciliolate, green zones lanceolate to ± diamond-shaped, apical, apices (often red-tipped) acute to obtuse-acuminate or acuminate, mucronulate, faces glabrous or sparsely strigillose.

Heads

in open, leafy, often pyramidal, paniculiform arrays, branches divaricate or branches 10 cm or less ascending, often arched and secund, sometimes racemiform.

[(5–)20–300+] in ± densely paniculiform arrays, branches divaricate to ascending, paniculiform, sometimes ± long-arching, leafy.

Cypselae

whitish or gray, oblong-obovoid, sometimes ± compressed, 1–1.5 × 0.5–0.7 mm, 4–6-nerved, faces sparsely strigillose;

pappi white, 3.5–4 mm.

dull purple or light brown, obovoid, ± compressed, 2–2.5 mm, 4–5-nerved, faces glabrous;

pappi white or ± rose-tinged, 2.5–4.5 mm.

2n

= 16, 32.

Symphyotrichum pilosum

Symphyotrichum cordifolium

Phenology Flowering Aug–Oct.
Habitat Rich, mostly mesic, rocky to loamy soils, open wooded slopes and bluffs, stream banks, moist ledges, swampy woods, border of beech-maple or oak-hickory forets, clearings, thickets, roadsides, along ditches, sometimes weedy in urban areas
Elevation 0–1200 m (0–3900 ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; VA; VT; WI; WV; BC; NB; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; GA; IA; IL; IN; KY; MA; MD; ME; MI; MN; MO; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; VA; VT; WI; WV; MB; NB; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

The ecology and cytogeography of Symphyotrichum pilosum were summarized by J. G. Chmielewski and J. C. Semple (2001b). The species is often confused with S. ericoides, which inhabits the same kinds of open, prairie-like habitats; the latter can be distinguished by its smaller heads and spine-tipped phyllary apices. Because of that, the name Aster ericoides has been misapplied often in floras and in the horticultural trade.

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

Symphyotrichum cordifolium has been introduced in British Columbia but has not persisted. In a morphometric analysis of infraspecific variation in the northeastern part of the range, A. Legault (1986) showed that the varieties described are not distinct and mostly represent phenotypic variants caused by growing conditions; likewise, diploid and tetraploid races could not be distinguished morphologically.

The type of Aster cordifolius var. laevigatus is conspecific with that of Symphyotrichum cordifolium. This name is the basionym of S. lowrieanum; therefore the latter cannot be considered distinct from S. cordifolium and is not recognized here. Most specimens initially identified as S. lowrieanum in herbaria have been re-determined as S. cordifolium. Some of the specimens, however, appear to correspond to the hybrid between S. cordifolium and S. laeve var. laeve, called S. ×schistosum (Steele) G. L. Nesom (syn. Aster schistosus Steele).

Symphyotrichum ×tardiflorum (Linnaeus) Greuter, Aghababian & Wagenitz [syn. Aster tardiflorus Linnaeus, A. novi-belgii Linnaeus subsp. tardiflorus (Linnaeus) A. G. Jones, A. novi-belgii var. tardiflorus (Linnaeus) A. G. Jones, Symphyotrichum novi-belgii (Linnaeus) G. L. Nesom var. tardiflorum (Linnaeus) G. L. Nesom] is the F1 hybrid between S. cordifolium and S. puniceum (J. Labrecque & Brouillet 1996; G. L. Nesom 1997; W. Greuter et al. 2005). Aster tardiflorus forma vestitus (Fernald) Fernald or var. vestitus Fernald is a hairy variant of the hybrid and is not recognized here; hairiness may be related to whichever species is the maternal parent. A. G. Jones (1989) reported hybrids with S. drummondii and S. urophyllum. She believed that var. moratum may be a hybrid with or an introgressant from S. drummondii, but this is not accepted by all authors. Symphyotrichum ×finkii (Rydberg) G. L. Nesom (syn. Aster finkii Rydberg), may be the hybrid of S. cordifolium and S. shortii. All such putative hybrids need to be confirmed.

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

Key
1. Stems sparsely to densely hirsute; leaves pilose; various substrates
var. pilosum
1. Stems glabrous; leaves glabrous or glabrate; mainly on calcareous substrates
var. pringlei
Source FNA vol. 20, p. 511. FNA vol. 20, p. 501.
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. 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. 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. pilosum var. pilosum, S. pilosum var. pringlei
Synonyms Aster pilosus, Aster ericoides var. pilosus Aster cordifolius, Aster cordifolius var. alvearius, Aster cordifolius var. furbishiae, Aster cordifolius var. incisus, Aster cordifolius subsp. laevigatus, Aster cordifolius var. laevigatus, Aster cordifolius var. lanceolatus, Aster cordifolius var. moratus, Aster cordifolius var. polycephalus, Aster cordifolius var. racemiflorus, Aster cordifolius subsp. sagittifolius, Aster cordifolius var. sagittifolius, Aster finkii var. moratus, Aster leiophyllus, Aster lowrieanus, Aster lowrieanus var. incisus, Aster lowrieanus var. lanceolatus, Aster sagittifolius, S. cordifolium var. furbishiae, S. cordifolium var. lanceolatum, S. cordifolium var. moratum, S. cordifolium var. polycephalum, S. cordifolium var. racemiflorum, S. lowrieanum, S. sagittifolium
Name authority (Willdenow) G. L. Nesom: Phytologia 77: 289. (1995) (Linnaeus) G. L. Nesom: Phytologia 77: 278. (1995)
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