Symphyotrichum prenanthoides |
Symphyotrichum dumosum |
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crooked-stem American-aster, crookedstem aster |
bushy American-aster, bushy aster, rice button aster |
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Habit | Perennials, 20–90(–120) cm, colonial; long-rhizomatous. | Perennials, (20–)30–100 cm, colonial or cespitose; usually long-rhizomatous, often thick, woody, sometimes short, or with short, stout caudices. |
Stems | 1(–3+), ascending to erect (usually flexuous, sometimes ± straight, sometimes stout, older often dark purple), glabrous proximally, moderately hirsute distally. |
1–5+, erect (straight, often slender, brittle), densely or sparsely strigose to glabrescent or glabrate. |
Leaves | thin, margins scabrous, apices mucronate, abaxial faces glabrous, midveins hispid to glabrate, adaxial scabrous; basal withering by flowering, petiolate (petioles slender or slightly winged, bases reddish, dilated, sheathing, ciliate), blades obovate to oblanceolate, 15–70 × 10–20 mm, bases attenuate, margins crenate-serrate, apices acute to obtuse; proximalmost cauline withering by flowering, proximal mostly persistent, petiolate to subpetiolate (petioles ± widely winged, bases dilated, strongly auriculate-clasping), blades ovate to lance-ovate or elliptic-lanceolate to oblanceolate, 80–160(–200) × 15–55 mm, progressively reduced distally, bases attenuate, margins sharply serrate (teeth mucronulate), apices acuminate to subcaudate; distal subpetiolate or sessile (petioles broadly winged, auriculate-clasping), blades oblanceolate to lanceolate, sometimes panduriform, 7–90 × 2–25 mm, progressively reduced distally, more sharply so on branches, bases attenuate (petiolate) or ± cuneate to auriculate-clasping and slightly constricted above auricles (panduriform), margins serrate or entire. |
firm, margins entire to crenulate-serrate, recurved, scabrous, apices sharply white-mucronate, abaxial faces glabrous or glabrate to sparsely strigillose, adaxial glabrous or glabrate to submarginally scabrous (short-strigose), cauline withering by flowering (except on array branches), often with axillary leaf clusters; basal withering by flowering, petiolate, petioles winged, sheathing, strigose-ciliate, blades oblanceolate to spatulate (often declined), 8–50 × 3–15 mm, bases attenuate to cuneate, margins crenate-serrate, apices obtuse or rounded to ± acute; proximal cauline (mostly declined) subpetiolate (petioles widely winged, clasping) or sessile (then not or barely clasping), blades linear-oblanceolate, 25–120 × 1.5–9 mm, bases cuneate to slightly attenuate; distal (ascending or spreading) sessile, blades oblong or linear-lanceolate to linear, 2–45 × 0.5–4 mm, reduced distally (abruptly on branches), bases cuneate to rounded, not clasping, margins entire or serrate. |
Peduncles | (8–)10–40 mm, sparsely to densely hispid, bracts lanceolate to linear-lanceolate, 3–12 mm, somewhat grading into phyllaries. |
slender, usually stiff (sometimes lax), (0.5–)1–5 cm (rarely subsessile), progressively reduced distally, usually not secund, sparsely strigillose or glabrous, bracts 5–16+, spreading to ascending, linear-oblong or -elliptic to subulate or linear, progressively reduced distally, grading into phyllaries. |
Involucres | campanulate, 5–6 mm. |
cylindro-campanulate, (3–)4.5–6.3 mm. |
Ray florets | 17–25(–30); corollas usually lavender to blue, rarely white, laminae 7.5–12(–15) × 1–2 mm. |
15–33; corollas pale blue, pink, or lavender to white, laminae (4–)5–7(–8) × 1–1.7 mm. |
Disc florets | 39–50(–65); corollas cream colored or light yellow becoming purple or brown, 3.5–5 mm, tubes ± equaling campanulate to funnelform throats (thinly puberulent), lobes triangular, 0.5–1 mm. |
15–30; corollas cream to pale yellow turning pink, 3.5–4.5 mm, tubes shorter than to equal to narrowly funnelform throats, lobes lanceolate, (0.4–)0.6–1.1 mm. |
Phyllaries | in 4–6 series, oblong-lanceolate or -oblanceolate, slightly constricted near middle (outer) to linear-lanceolate or linear (inner), ± unequal (flexible), bases indurate 1/5–1/2, margins ± narrowly hyaline, scarious, erose, sometimes ciliolate distally, green zones lanceolate to linear-lanceolate (inner), often distally foliaceous, sometimes outer ± entirely so, apices spreading to ± squarrose, acute to acuminate, mucronulate, abaxial faces sparsely hirsutulous to glabrate or glabrous, adaxial glabrous or sparsely hirsutulous. |
in 4–6 series, appressed or slightly spreading, oblong-oblanceolate (outer) to linear-oblanceolate or linear (innermost), strongly unequal, bases indurate (1/2–)2/3–4/5, margins hyaline, scarious, erose, distally ciliolate, green zones oblanceolate to elliptic (subapical), apices acute to obtuse (scarious), sometimes faintly reddish, mucronulate, faces usually glabrous, sometimes glabrate. |
Heads | in broad, ± flat, corymbo-paniculiform arrays, branches often purplish, divaricate to ascending, slender. |
in remote, diffuse, open, paniculiform arrays, branches numerous, ascending to stiffly ascending, secondary ones stiff, racemiform (usually not secund). |
Cypselae | dull purple or stramineous with purple streaks or purplish-tinged, cylindro-oblanceoloid to obovoid, ± compressed, 2–3(–3.5) mm, 4–6-nerved, faces sparsely to moderately strigillose; pappi sordid, 3.5–4.5 mm. |
pink or stramineous with pink streaks, or gray (± dark, nerves stramineous), oblong-obovoid, sometimes ± compressed, 1.5–2.5 mm, 3–4-nerved (nerves prominent), faces strigillose; pappi white to sordid, 4 mm. |
2n | = 32. |
= 16, 32. |
Symphyotrichum prenanthoides |
Symphyotrichum dumosum |
|
Phenology | Flowering Aug–Oct. | Flowering Aug–Oct. |
Habitat | Moist or swampy grounds, woods, thickets, meadows, seeps, stream banks, roadsides | Open or wooded, moist or wet soils, bogs, fens, sedge meadows, marshes, swamps, flood plains, sandy or calcareous flats, loamy prairies, old fields, sandhills, flatwoods, hammocks, pine-hickory woods, oak or pine thickets, secondary woods, sandy to mucky or marly shores of lakes and ponds, interdunal hollows |
Elevation | 100–1500 m (300–4900 ft) | 0–700 m (0–2300 ft) |
Distribution |
CT; DC; DE; IA; IL; IN; KY; MA; MD; MI; MN; NC; NJ; NY; OH; PA; VA; WI; WV; ON
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AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KY; LA; MA; MD; ME; MI; MO; MS; NC; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WI; WV; NB; ON
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Discussion | Symphyotrichum prenanthoides is of conservation concern in Canada and in a number of states. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Symphyotrichum dumosum is introduced in New Brunswick. It is widely cultivated. It can hybridize with S. racemosum and S. lanceolatum var. interior (A. G. Jones 1989). G. L. Nesom (1994b) and J. C. Semple et al. (2002) recognized several varieties within the complex: var. dumosum [syn. Aster coridifolius Michaux, A. dumosus Linnaeus var. coridifolius (Michaux) Torrey & A. Gray]; var. gracilipes (Wiegand) G. L. Nesom (syn. A. dumosus var. gracilipes Wiegand); var. pergracile (Wiegand) G. L. Nesom (syn. A. dumosus var. pergracile Wiegand); var. strictior (Torrey & A. Gray) G. L. Nesom [syn. A. dumosus var. strictior Torrey & A. Gray, A. dumosus var. dodgei Fernald, S. dumosum var. dodgei (Fernald) G. L. Nesom, the latter possibly the hybrid S. dumosum × S. boreale fide G. L. Nesom 1997]; and var. subulifolium (Torrey & A. Gray) G. L. Nesom (syn. A. dumosus var. subulifolium Torrey & A. Gray). Some of these taxa may deserve higher rank. More work is needed in the complex, however, before a coherent taxonomy can be achieved. G. L. Nesom (1997) recognized also a southern pine flatwoods entity called Symphyotrichum kralii G. L. Nesom, based on the illegitimately named Aster pinifolius Alexander (not Nees, nor F. Mueller). The type of A. pinifolius, however, appears to be conspecific with that of S. simmondsii. At present, it seems best to wait for full investigation before formally recognizing such taxa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 527. | FNA vol. 20, p. 514. |
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum |
Sibling taxa | ||
Synonyms | Aster prenanthoides | Aster dumosus, Aster coridifolius |
Name authority | (Muhlenberg ex Willdenow) G. L. Nesom: Phytologia 77: 290. (1995) | (Linnaeus) G. L. Nesom: Phytologia 77: 280. (1995) |
Web links |