Symphyotrichum subulatum |
Symphyotrichum prenanthoides |
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annual saltmarsh American-aster, annual saltmarsh aster, annual saltmarsh or eastern annual saltmarsh aster, aster subulé, eastern annual saltmarsh aster, Southwestern annual saltmarsh aster |
crooked-stem American-aster, crookedstem aster |
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Habit | Annuals, (10–)30–150 cm; tap-rooted. | Perennials, 20–90(–120) cm, colonial; long-rhizomatous. | ||||||||||||||||
Stems | 1, erect (often with purple or purplish brown areas), glabrous or glabrate, sometimes strigillose in leaf axils. |
1(–3+), ascending to erect (usually flexuous, sometimes ± straight, sometimes stout, older often dark purple), glabrous proximally, moderately hirsute distally. |
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Leaves | thin (green to dark green), margins often strigilloso-ciliolate, faces glabrous; basal withering by flowering, long-petiolate (petiole bases sheathing), sparsely ciliate, blades ovate to oblanceolate, 10–90 × 6–14 mm, bases attenuate to cuneate, rounded, margins entire or serrulate or crenulate, apices rounded, obtuse, or acute; proximal cauline withering by flowering, petiolate, subpetiolate, or sessile, blades narrowly lanceolate or subulate, 20–100(–200) × 1.5–10(–20) mm, bases attenuate, margins subentire, entire, or serrulate, apices acute to acuminate; distal sessile, blades narrowly lanceolate to subulate, 5–113 × 0.5–5.5 mm, apices acuminate. |
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. |
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Peduncles | (0.2–)0.5–4 cm, bracts 4–8(–17). |
(8–)10–40 mm, sparsely to densely hispid, bracts lanceolate to linear-lanceolate, 3–12 mm, somewhat grading into phyllaries. |
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Involucres | cylindric to turbinate, 5–7(–8.2) mm. |
campanulate, 5–6 mm. |
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Ray florets | 16–30(–54) in 1–3 series; corollas white, pink, or lavender, laminae 1.3–7 × 0.2–1.3 mm. |
17–25(–30); corollas usually lavender to blue, rarely white, laminae 7.5–12(–15) × 1–2 mm. |
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Disc florets | 4–10(–13); corollas yello, sometimes tinged with purple, 3.4–5.2 mm, throats narrowly funnelform, lobes ± spreading to erect, narrowly triangular, 0.3–0.7 mm, glabrous. |
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. |
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Phyllaries | in 3–5 series, broadly or narrowly lanceolate to subulate, unequal, bases indurate, margins hyaline, often purple-tinged, entire, green zones lanceolate (usually narrow, sometimes broad and covering most of distal portion), apices acute, faces glabrous. |
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. |
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Heads | (10–) 30–100(–150), in open, diffuse, paniculiform arrays. |
in broad, ± flat, corymbo-paniculiform arrays, branches often purplish, divaricate to ascending, slender. |
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Cypselae | light brown to purple, narrowly obovoid to fusiform, sometimes ± compressed, (1.2–)1.5–2.7(–3) mm, 5-nerved, faces sparsely strigillose; pappi white, (3–)3.5–5.5 mm. |
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. |
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2n | = 32. |
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Symphyotrichum subulatum |
Symphyotrichum prenanthoides |
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Phenology | Flowering Aug–Oct. | |||||||||||||||||
Habitat | Moist or swampy grounds, woods, thickets, meadows, seeps, stream banks, roadsides | |||||||||||||||||
Elevation | 100–1500 m (300–4900 ft) | |||||||||||||||||
Distribution |
AL; AR; AZ; CA; CT; DE; FL; GA; IL; IN; KS; LA; MA; MD; ME; MI; MS; NC; NE; NH; NJ; NM; NV; NY; OH; OK; PA; RI; SC; TN; TX; UT; VA; NB; ON; Mexico; Central America; South America; West Indies; Bermuda [Widely introduced worldwide]
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CT; DC; DE; IA; IL; IN; KY; MA; MD; MI; MN; NC; NJ; NY; OH; PA; VA; WI; WV; ON
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Discussion | Varieties 5 (5 in the flora). Five varieties of Symphyotrichum subulatum are recognized for North America based on differences in chromosome number, ray lamina color and size, array shapes, number of series of ray florets, number of disc and ray florets, and other, more cryptic characters (S. D. Sundberg 2004). These varieties were treated as species by G. L. Nesom (1994b, 2005d). Variety ligulatum is apparently an obligate outcrosser and is the least variable variety (Sundberg). Other varieties are self-compatible, which could facilitate the fixation of mutations in populations. The five varieties are nearly entirely allopatric, and intermediates between pairs of varieties are not uncommon where they approach one another. Populations that are intermediate in ray lamina size between vars. ligulatum and parviflorum are widespread in southern Texas, New Mexico, Arizona, and northern Mexico. Intermediates between vars. elongatum and parviflorum and between vars. elongatum and subulatum occur in Florida. Despite these observations, hybridization experiments and chromosome number differences suggest that the varieties are mostly reproductively isolated (S. D. Sundberg 1986, 2004). In older floras the name Aster exilis Elliott has been applied to Symphyotrichum subulatum vars. ligulatum and parviflorum. The status of this name is uncertain; the type specimen has been lost and the description of the plant is inadequate for determining the taxon to which the name should be applied (G. L. Nesom 1994b; S. D. Sundberg 2004). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Symphyotrichum prenanthoides is of conservation concern in Canada and in a number of states. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 480. | FNA vol. 20, p. 527. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Aster subulatus | Aster prenanthoides | ||||||||||||||||
Name authority | (Michaux) G. L. Nesom: Phytologia 77: 293. (1995) | (Muhlenberg ex Willdenow) G. L. Nesom: Phytologia 77: 290. (1995) | ||||||||||||||||
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