Taxon 31: 359. 1982.
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. 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 lanceovate or lanceolate to linear, 7–45 × 1–14 mm, progressively reduced distally (abruptly so in arrays), bases auriculate and ± clasping to rounded, margins entire. Heads in broad, sometimes ± flat-topped, paniculiform arrays, branches stiffly ascending (rarely arching), leafy with small, gradually reduced branch leaves. 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. Involucres campanulate to cylindro-campanulate, (4.2–) 5–7 (–8) mm. 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. 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. 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. 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.
Alta., B.C., Man., N.B., Ont., Que., Sask., Yukon, Ala., Ark., Calif., Colo., Conn., D.C., Del., Fla., Ga., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Mass., Md., Mich., Minn., Miss., Mo., Mont., N.C., N.Dak., N.H., N.J., N.Mex., N.Y., Nebr., Nev., Ohio, Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., Wyo., ne Mexico, in other areas of Mexico, Central America, Europe
Varieties 4 (4 in the flora).
|1||Leaves lanceolate to ovate, conspicuously auriculate-clasping, lengths less than 5 times widths||> 2|
|1||Leaves linear-lanceolate to linear, slightly auriculate-clasping, lengths often 5 times widths||> 3|
|2||Phyllaries strongly unequal, green apical zones diamond-shaped||Symphyotrichum laeve var. laeve|
|2||Phyllaries unequal, green apical zones lanceolate||Symphyotrichum laeve var. geyeri|
|3||Basal leaves withering by flowering, cauline linear-lanceolate||Symphyotrichum laeve var. concinnum|
|3||Leaves mostly basal and proximal at flowering, mostly linear||Symphyotrichum laeve var. purpuratum|
"thick" is not a number."thick" is not a number.