Symphyotrichum racemosum |
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small white American-aster, small white or smooth white Oldfield aster, smooth white Oldfield aster |
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Habit | Perennials, 30–90(–100) cm, colonial or cespitose; long-rhizomatous or with woody caudices. |
Stems | 1–3+, erect (straight), glabrous or glabrate. |
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. |
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. |
Involucres | cylindric, (2.5–)3.5–4.5(–5.5) mm. |
Ray florets | (12–)16–20; corollas usually white, rarely pink, laminae 5–8 × 0.5–1.2 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. |
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. |
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. |
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. |
2n | = 16. |
Symphyotrichum racemosum |
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Phenology | Flowering Aug–Oct. |
Habitat | Moist to wet, often alluvial soils, often brackish, marshes, savannas, bogs, wet meadows, prairie swales, swamps, borders of swamps, open bottomwoods |
Elevation | 0–200 m (0–700 ft) |
Distribution |
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
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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. |
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum |
Sibling taxa | |
Synonyms | Aster racemosus, Aster brachypholis |
Name authority | (Elliott) G. L. Nesom: Phytologia 77: 290. (1995) |
Web links |