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small white American-aster, small white or smooth white Oldfield aster, smooth white Oldfield aster

scaleleaf aster

Habit Perennials, 30–90(–100) cm, colonial or cespitose; long-rhizomatous or with woody caudices. Perennials, 30–120 cm, cespitose; with herbaceous or thick, woody, sometimes cormoid caudices.
Stems

1–3+, erect (straight), glabrous or glabrate.

5+, erect to scandent-sprawling (brown, branched from middle), moderately to densely finely hairy.

Leaves

thin, margins often ± revolute, scabrous, apices mucronate to mucronulate, faces glabrous or abaxial minutely pilosulous, cauline with clusters of smaller leaves in most axils;

basal withering by flowering (new vernal rosettes often present), petiolate (petioles narrowly winged, sheathing, strigoso-ciliate), blades spatulate to oblanceolate, 5–40 × 5–15 mm, bases attenuate or cuneate to rounded, margins crenate-serrate, apices obtuse to acuminate;

proximal cauline withering by flowering, petiolate or subpetiolate (proximalmost) or sessile (petioles winged, sparsely long strigoso-ciliate), blades elliptic or elliptic-lanceolate to lanceolate or linear-lanceolate, 20–70 × 3–20 mm, progressively reduced distally, bases clasping, margins becoming short-ciliate distally;

distal (ascending or spreading) usually sessile, sometimes subpetiolate, blades linear-lanceolate to linear, 5–60+ × 1–8 mm, notably unequal in size, reduced distally, abruptly so on branches, bases cuneate to attenuate, margins serrulate or entire.

(yellowish green) thick, firm, margins entire;

basal early deciduous, sessile or subpetiolate, blades (3-nerved) oblanceolate to obovate, 10–43 × 7–15 mm, bases cuneate, margins scabrous, apices acute to obtuse, faces sparsely finely scabrous;

proximal cauline sessile, blades narrowly obovate to oblanceolate, 20–35 × 5–13 mm, bases auriculate-clasping, margins finely scabrous, apices acute to obtuse, faces finely scabrous, shiny;

distal sessile, blades lanceolate to linear, 3–10 × 1–4 mm, gradually reduced to bracts distally, bases subclasping and adnate to stem for 1/2+ length, apices narrowly acute, white-spinulose, faces finely scabrous, viscid, minutely stipitate-glandular.

Peduncles

slender, 0.2–3+ cm or subsessile, hairy in lines, bracts 5–15, linear-elliptic to acicular, 1–2 mm, glabrous, grading into phyllaries.

densely short-strigose, glandular, bracts linear, adnate, densely short-strigose.

Involucres

cylindric, (2.5–)3.5–4.5(–5.5) mm.

campanulate, 4–6.5 mm.

Ray florets

(12–)16–20;

corollas usually white, rarely pink, laminae 5–8 × 0.5–1.2 mm.

10–20;

corollas light to dark lavender, laminae 5–8 × 0.5–1.5 mm.

Disc florets

10–20(–25);

corollas cream or pale yellow becoming pink or red, (2.5–)3–4.5 mm, tubes shorter than narrowly funnelform throats, lobes recurved to erect, lanceolate, 0.5–1 mm.

12–25;

corollas yellow, 3.7–7 mm, throats narrowly funnelform, lobes triangular, 0.4–0.8 mm.

Phyllaries

in 4–6 series, appressed or outer ± spreading, oblong-lanceolate to linear (innermost) , unequal, bases indurate 1/4–1/2, margins narrowly scarious, hyaline, ciliolate, green zones oblanceolate to linear-oblanceolate, apices acute to acuminate, mucronate, sometimes lightly purple-tinged, faces glabrous.

in 4–5 series, oblong to oblanceolate, strongly unequal, bases (tan) ± indurate, margins hyaline, finely scabrous, green zones lenticular, in distal 1/4–2/5, apices obtuse, mucronate to finely subspinulose, faces scabrellous-puberulent, stipitate-glandular.

Heads

in diffuse, ± pyramidal, paniculiform arrays, branches ± lax, spreading horizontally or arching, racemiform, subtended by patent to reflexed branch leaves, often crowded but not (or barely) secund.

in ± open, paniculiform arrays, branches initially patent then ascending or divaricate.

Cypselae

gray to tan, obovoid, ± compressed, 1–1.8 mm, 4–5-nerved (faint), faces sparsely strigillose or sericeus;

pappi white, 2.5–3.5 mm.

tan to brown, obovoid, not compressed, 2–2.5 mm, 6–10-nerved (faint), faces sparsely strigose;

pappi tan, 3.75–8 mm.

2n

= 16.

= 20.

Symphyotrichum racemosum

Symphyotrichum adnatum

Phenology Flowering Aug–Oct. Flowering Oct–Dec.
Habitat Moist to wet, often alluvial soils, often brackish, marshes, savannas, bogs, wet meadows, prairie swales, swamps, borders of swamps, open bottomwoods Sandy, clayey soils, sandhills, oak-pine scrub, open pine flatwoods, roadsides
Elevation 0–200 m (0–700 ft) 0–100+ m (0–300+ ft)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MO; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WV; NB; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; LA; MS
[WildflowerSearch map]
[BONAP county map]
Discussion

Symphyotrichum racemosum is introduced in Canada. The species is cultivated commercially under the name Aster ericoides cv. ‘Spray’. A. G. Jones (1989) reported hybridization with S. dumosum, S. lateriflorum, S. lanceolatum var. interior, and S. ontarionis. The name Aster vimineus Lamarck has been misapplied to this taxon.

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

Source FNA vol. 20, p. 515. FNA vol. 20, p. 491.
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. 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. 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. urophyllum, S. walteri, S. welshii, S. yukonense, S. ×amethystinum
Synonyms Aster racemosus, Aster brachypholis Aster adnatus, Lasallea adnata, Virgulus adnatus
Name authority (Elliott) G. L. Nesom: Phytologia 77: 290. (1995) (Nuttall) G. L. Nesom: Phytologia 77: 275. (1995)
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