Symphyotrichum laeve |
Symphyotrichum laeve var. laeve |
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aster lisse, Geyer's aster, smooth American-aster, smooth aster, smooth blue aster |
smooth blue aster |
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Habit | Perennials (15–)20–70(–120) cm, cespitose; stoutly short-rhizomatous, with thick, woody caudices or a few, long rhizomes. | |||||||||||||
Stems | 1–5+, erect (straight, glaucous, sometimes reddish proximally), glabrous, sometimes sparsely hirsute distally. |
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Leaves | (glaucous) thick, firm, ± fleshy, margins crenate-serrate or -serrulate or entire, scabridulous, apices mucronulate, faces glabrous; basal usually withering by flowering or sometimes persistent (var. purpuratum), petiolate (petioles ± winged, bases dilated, sheathing), blades spatulate or oblong to ovate or lanceolate-ovate, 30–200 × 10–25(–30) mm, bases attenuate or cuneate to rounded, margins crenate-serrate to serrulate, apices acute to obtuse or rounded; proximal cauline often withering by flowering, petiolate or subsessile or sessile (petioles narrowly to broadly winged, clasping), blades ovate or oblong-ovate to lanceolate or linear-lanceolate, sometimes ± panduriform, (40–)80–150(–180) × (10–)20–45 mm, bases attenuate to rounded or ± shallowly auriculate-clasping, margins entire or shallowly crenate-serrate, minutely scabrous, apices acute or obtuse, callus-pointed; distal sessile, blades lance-ovate or lanceolate to linear, 7–45 × 1–14 mm, progressively reduced distally (abruptly so in arrays), bases auriculate and ± clasping to rounded, margins entire. |
lanceolate to ovate, conspicuously auriculate-clasping, less than 5 times as long as wide. |
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Peduncles | 0.2–6+ cm, glaucous, glabrous or puberulent in lines, bracts 3–6, densely spaced, subulate or linear-lanceolate to linear, subclasping, apices sometimes purplish, grading into phyllaries. |
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Involucres | campanulate to cylindro-campanulate, (4.2–)5–7(–8) mm. |
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Ray florets | (11–)13–23(–34); corollas usually pale to dark blue or purple, seldom white, laminae (6–)7.2–11.3(–14.6) × 1.5–2.5 mm. |
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Disc florets | (17–)19–33(–43); corollas yellow turning purplish red, 3.5–6.1 mm, tubes slightly shorter than funnelform throats, lobes triangular, (0.4–)0.6–1 mm. |
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Phyllaries | in 4–6 series, appressed, subulate or lanceolate (outer) to oblong-lanceolate or linear-lancolate or -oblanceolate, unequal (sometimes appearing subequal), bases indurate 1/2–3/4, margins scarious, erose, hyaline, ciliolate distally, green zones mostly diamond-shaped to ± lanceolate (some inner, or most in var. geyeri), apices acute to acuminate, sometimes ± obtuse, red-mucronate or apiculate, faces glabrous. |
strongly unequal, apical green zones diamond-shaped. |
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Heads | in broad, sometimes ± flat-topped, paniculiform arrays, branches stiffly ascending (rarely arching), leafy with small, gradually reduced branch leaves. |
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Cypselae | deep purple to brown, oblong-obovoid, compressed, 2–3.5 mm, 4–5-nerved, faces glabrous or glabrate; pappi tawny to red- or rose-tinged, 5–7 mm. |
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2n | = 48. |
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Symphyotrichum laeve |
Symphyotrichum laeve var. laeve |
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Phenology | Flowering (Jul–)Aug–Oct. | |||||||||||||
Habitat | Open, dry habitats, mixed- and tallgrass prairies, open, dry oak and other deciduous forests, glades and alvars, roadsides | |||||||||||||
Elevation | 0–1000+ m (0–3300+ ft) | |||||||||||||
Distribution |
AL; AR; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; ON; QC; SK; YT; ne Mexico [Introduced in other areas of Mexico, Central America, Europe]
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AL; AR; CT; DC; DE; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; ND; NE; NH; NJ; NY; OH; PA; RI; SD; TN; VA; VT; WI; WV; MB; NB; ON; QC; NC [Introduced in Mexico, West Indies, Central America, South America, Europe] |
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Discussion | Varieties 4 (4 in the flora). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Variety laeve is found in the tallgrass prairies area and midwestern deciduous forest, mainly west of the Appalachian Mountains, but reaching the Atlantic from New Jersey to New England. It was introduced in Quebec and New Brunswick; it is also widely introduced outside North America. It is sold in the horticultural trade. Aster laevis forma beckwithiae House is a white-rayed phenotype that is not recognized here. Hybrids of this variety have been reported with Symphyotrichum ciliolatum, S. cordifolium, S. drummondii, S. lanceolatum, S. lateriflorum, S. oolentangiense, and S. urophyllum. The hybrid with S. praealtum was described as Aster novi-belgii Linnaeus var. litoreus A. Gray [S. novi-belgii var. litoreum (A. Gray) G. L. Nesom; J. Labrecque and L. Brouillet 1996]. Symphyotrichum ×versicolor (Willdenow) G. L. Nesom (Aster versicolor Willdenow) is the hybrid between S. laeve var. laeve and S. novi-belgii var. novi-belgii. It is of garden origin and has escaped locally in Europe but has not been reported in North America. Symphyotrichum ×gravesii (E. S. Burgess) G. L. Nesom (Aster gravesii E. S. Burgess), originally reported from Connecticut, may be the hybrid between S. laeve var. laeve and S. dumosum, though annotations suggest that the second parent might be S. cordifolium. Symphyotrichum ×woldenii (Rydberg) G. L. Nesom (Aster woldenii Rydberg), initially reported from Iowa, is possibly the hybrid between S. laeve var. laeve and S. praealtum, or S. oolentangiense and S. praealtum. The question of exact parentage is unresolved. Distinction between var. laeve and var. geyeri is based on phyllary morphology. The two varieties appear to intergrade in the northeastern prairies but are mostly well defined at the extremes of the range, though plants in the western United States sometimes appear similar to var. laeve. These varieties are much more similar to each other than either is to var. concinnum or var. purpuratum and should be grouped in subsp. laeve. Alternately, var. geyeri could be considered a synonym of var. laeve. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 508. | FNA vol. 20, p. 508. | ||||||||||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum > Symphyotrichum laeve | ||||||||||||
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Subordinate taxa | ||||||||||||||
Synonyms | Aster laevis | |||||||||||||
Name authority | (Linnaeus) Á. Löve & D. Löve: Taxon 31: 359. (1982) | unknown | ||||||||||||
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