Symphyotrichum lanceolatum

(Willdenow) G. L. Nesom

Phytologia 77: 284. 1995.

Common names: Lance-leaved or panicled or white panicled aster aster lancéolé
Illustrated
Basionym: Aster lanceolatus Willdenow Sp. Pl. 3: 2050. 1803
Treatment appears in FNA Volume 20. Mentioned on page 466, 467, 469, 475, 477, 501, 509, 516.

Perennials, 30–150 (–200) cm, colonial; long-rhizomatous (rhizomes usually white, thick, contorted). Stems 1, erect (straight, stout), glabrous or hairy. Leaves thin, scabrous, apices mucronate, abaxial faces glabrous (vein areoles indistinct, elongate), adaxial glabrous or sparsely scabrous (var. hesperium); basal withering by flowering, petiolate to subpetiolate (petioles winged, ciliate, bases dilated, sheathing), blades elliptic-oblanceolate or obovate to suborbiculate, 10–80 × 5–20 mm, cuneate to attenuate, margins crenate-serrate, apices acute to obtuse or rounded; proximal cauline withering by flowering, sessile or subsessile, blades lanceovate or oblanceolate to linear-lanceolate, (40–) 50–150 × (3–) 10–20 (–35) mm, progressively reduced distally, bases cuneate, ± decurrent, margins serrate, apices acute to acuminate; distal sessile, blades oblanceolate to linear, 30–100 (–140) mm, only slightly reduced distally, bases cuneate, margins entire. Heads in ample or diffuse to narrow, elongate, leafy, paniculiform arrays, branches ± ascending, rarely secund, branch leaves often longer than pedicels. Peduncles 0.5–5 cm, ± pilose, bracts 1–3 (–5), linear-oblanceolate to lanceolate, foliaceous, ciliate. Involucres campanulate to cylindric, 3–8 mm. Phyllaries in (3–) 4–6 series, appressed or slightly spreading, linear-lanceolate to linear (innermost), sometimes slightly dilated distally, ± strongly unequal to subequal (var. hesperium), bases indurate 1/4–1/2, margins scarious, erose, hyaline, sparsely ciliolate, green zones lanceolate to linear-lanceolate, outer sometimes foliaceous (particularly var. hesperium), apices acute to acuminate (outer) or acuminate to caudate (inner), mostly mucronulate, abaxial faces glabrous, adaxial sparsely strigillose. Ray-florets 16–50; corollas white to pinkish or pale blue-violet, laminae 3–10 (–14) × 0.5–1.3 mm. Disc-florets (13–) 20–40 (–52); corollas yellow becoming purple, 2.8–5.8 mm, tubes shorter than funnelform throats, lobes sometimes ± spreading, triangular, 0.4–1.2 mm. Cypselae gray or tan, obovoid, ± compressed, 1.5–2 mm, 4–5-nerved, faces sparsely strigillose; pappi white to sordid or tawny, 5.5–6 mm.

Distribution

V20-1155-distribution-map.gif

Alta., B.C., Man., N.B., N.S., N.W.T., Nfld. and Labr. (Nfld.), Ont., P.E.I., Que., Sask., Ala., Ariz., Ark., Calif., Colo., Conn., D.C., 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, Okla., Oreg., Pa., R.I., S.C., S.Dak., Tenn., Tex., Utah, Va., Vt., W.Va., Wash., Wis., Wyo., in Europe

Discussion

Varieties 5 (5 in the flora).

Varieties of Symphyotrichum lanceolatum are sometimes grouped into two subspecies: subsp. hesperium (var. hesperium) and subsp. lanceolatum (the other four varieties). J. C. Semple and J. G. Chmielewski (1987) provided maps of the five taxa. The ranges of var. hesperium and var. lanceolatum overlap in the prairies and in the boreal zone from Alberta to the Clay Belt of northern Ontario. The ranges of the other three varieties do not overlap with that of var. hesperium, but they all overlap each other and with var. lanceolatum in the Midwest. The ecology and cytogeography of the species were summarized by Chmielewski and Semple (2001). The name Aster tradescantii has sometimes been misapplied to this species.

Key

1 Outer phyllaries 2/3 + length of inner ones; heads usually subtended by large foliaceous bracts; cordilleras and prairies (subsp. hesperium) Symphyotrichum lanceolatum var. hesperium
1 Outer phyllaries 1/3 – 2/3 length of inner ones; heads not usually subtended by large foliaceous bracts; prairies eastwards (subsp. lanceolatum) > 2
2 Stems stout, moderately to densely short-woolly from bases; Great Lakes region to se Manitoba Symphyotrichum lanceolatum var. hirsuticaule
2 Stems stout to slender, glabrous or at most hairy in lines at bases > 3
3 Heads congested on lateral branches of arrays; involucres 3–4 mm; midwestern United States, s Ontario, s Quebec Symphyotrichum lanceolatum var. interior
3 Heads not congested or congested only distally on lateral branches of arrays; involucres 3.6–5.6 mm (mostly longer than 4 mm) > 4
4 Leaves broadly oblanceolate, not much reduced in arrays; involucres usually 4–5.5 mm; rays white Symphyotrichum lanceolatum var. latifolium
4 Leaves linear to oblanceolate, reduced in arrays; involucres 3.5–5(–6) mm; rays white to purplish Symphyotrichum lanceolatum var. lanceolatum

"thin" is not a number.

scabrous +  and glabrous +
not tailed +, rounded +  and obtuse +
petiolate +  and subpetiolate +
distinct +
1 cm10 mm <br />0.01 m <br /> (8 cm80 mm <br />0.08 m <br />) +
subequal +
scarious +
5mm +  and 20mm +
usually triangular +  and linear +
usually deltate +  and lanceolate +
spiciform +, racemiform +, paniculiform +  and corymbiform +
indeterminate +  and determinate +
Luc Brouillet +, John C. Semple +, Geraldine A. Allen +, Kenton L. Chambers +  and Scott D. Sundberg† +
(Willdenow) G. L. Nesom +
cuneate +  and decurrent +
indurate +
Aster lanceolatus +
subsessile +, sessile +, petiolate +  and subpetiolate +
10 cm100 mm <br />0.1 m <br /> (14 cm140 mm <br />0.14 m <br />) +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
1 cm10 mm <br />0.01 m <br /> (8 cm80 mm <br />0.08 m <br />) +
oblanceolate;linear +
reduced +
3 cm30 mm <br />0.03 m <br /> (10 cm100 mm <br />0.1 m <br />) +
10mm;20mm +
rugulose +  and muricate +
linear-oblanceolate +  and lanceolate +
barbellulate +  and barbellate +
sessile +  and petiolate +
Lance-leaved or panicled or white panicled aster +  and aster lancéolé +
not 2-lipped +  and actinomorphic +
yellow becoming purple +, white +  and pinkish or pale blue-violet +
at maturity , more or less ampliate , tubes usually shorter +
0.28 cm2.8 mm <br />0.0028 m <br /> (0.58 cm5.8 mm <br />0.0058 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
tan +  and gray +
strigillose +  and glabrous +
compressed +  and obovoid +
fertile +  and bisexual +
fertile +  and bisexual +
Alta. +, B.C. +, Man. +, N.B. +, N.S. +, N.W.T. +, Nfld. and Labr. (Nfld.) +, Ont. +, P.E.I. +, Que. +, Sask. +, Ala. +, Ariz. +, Ark. +, Calif. +, Colo. +, Conn. +, D.C. +, 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 +, Okla. +, Oreg. +, Pa. +, R.I. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Utah +, Va. +, Vt. +, W.Va. +, Wash. +, Wis. +, Wyo. +  and in Europe +
strigillose +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
disciform +  and radiate +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
campanulate;cylindric +
0.3 cm3 mm <br />0.003 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
1 cm10 mm <br />0.01 m <br /> (1.4 cm14 mm <br />0.014 m <br />) +
2 (?) +  and 5 (?) +
0.5mm;1.3mm +
sessile +  and petiolate +
cauline +  and basal +
decurrent +
triangular +
petiolate +  and subpetiolate +
entire +, serrate +  and crenate-serrate +
10mm;80mm +
acute +  and obtuse or rounded +
5mm +  and 20mm +
2-carpellate +
white +  and sordid or tawny +
persistent +
25 +  and 40 +
0.55 cm5.5 mm <br />0.0055 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
spreading +  and appressed +
dilated +, linear-lanceolate +  and linear +
less strongly unequal +  and subequal +
4 cm40 mm <br />0.04 m <br /> (5 cm50 mm <br />0.05 m <br />) +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
styliferous +, neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
flat;slightly convex +
semple1987a +
exalbuminous +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
0.1mm;0.2mm +
Illustrated +
branched +  and simple +
appendaged +  and truncate +
papillate +  and smooth +
Aster sect. Heterastrum +  and Aster subg. Symphyotrichum +
Symphyotrichum lanceolatum +
Symphyotrichum sect. Symphyotrichum +
species +
funnelform-campanulate +  and cylindric +
ampliate +
150 cm1,500 mm <br />1.5 m <br /> (200 cm2,000 mm <br />2 m <br />) +
30 cm300 mm <br />0.3 m <br /> (150 cm1,500 mm <br />1.5 m <br />) +
tree +, shrub +  and subshrub +
lanceolate +  and linear-lanceolate +