Symphyotrichum lanceolatum |
Symphyotrichum ×amethystinum |
|||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
aster lancéolé, lance-leaf American-aster, lance-leaf aster, lance-leaf or panicle or white panicle aster, marsh aster, panicle aster, tall white aster, western willow aster, white-panicle aster |
amethyst aster, aster, hybrid aster |
|||||||||||||||||
Habit | Perennials, 30–150(–200) cm, colonial; long-rhizomatous (rhizomes usually white, thick, contorted). | Perennials, cespitose, 30–120 cm; with thick, woody, short-branched caudices at ends of fleshy rhizomes. | ||||||||||||||||
Stems | 1, erect (straight, stout), glabrous or hairy. |
1–5+, erect (light brown to grayish brown), densely hispidulo-hirsute. |
||||||||||||||||
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 lance-ovate 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. |
light green, thin to firm; basal withering by flowering, sessile, blades oblanceolate, 10–40 × 3–10 mm, attenuate, margins usually entire, rarely remotely serrate, piloso-ciliate, apices obtuse, rounded to mucronulate, faces sparsely to moderately strigose; proximal cauline sometimes persistent by flowering, sessile, blades linear or oblong to elliptic-oblanceolate, 40–60 × 3–10 mm, bases rounded or slightly clasping, margins entire, scabrous, apices acute to obtuse, faces ± copiously hirsute; distal sessile, blades oblanceolate, 15–45 × 2–3(–4.5) mm, progressively reduced distally, bases cuneate, margins entire, apices acute, white-spine-tipped, faces sparsely strigose. |
||||||||||||||||
Peduncles | 0.5–5 cm, ± pilose, bracts 1–3(–5), linear-oblanceolate to -lanceolate, foliaceous, ciliate. |
hispid, bracts 1–3+, oblong-lanceolate, 3–5 mm, not grading into phyllaries. |
||||||||||||||||
Involucres | campanulate to cylindric, 3–8 mm. |
campanulate to hemispheric, 4–6 mm. |
||||||||||||||||
Ray florets | 16–50; corollas white to pinkish or pale blue-violet, laminae 3–10(–14) × 0.5–1.3 mm. |
20–35; corollas azure blue to violet or lavender, laminae 5–10 × 0.6–1.2 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. |
20–30+; corollas light yellow turning pinkish to purple, 3–4 mm, tubes ca. 1/2 narrowly funnelform throats, lobes triangular, 0.5–0.7 mm, glabrous. |
||||||||||||||||
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. |
in 3–5 series, linear-lanceolate, ± unequal to subequal, bases ± indurate, margins hyaline proximally, outer distally hispido-scabrous, green zones diamond-shaped, restricted to distal 1/2–1/4, apices (outer) spreading to reflexed, acute, subspinulose, (inner) acuminate, purplish, faces (outer) scabroso-puberulent or strigose, eglandular, inner distally stipitate-glandular. |
||||||||||||||||
Heads | in ample or diffuse to narrow, elongate, leafy, paniculiform arrays, branches ± ascending, rarely secund, branch leaves often longer than pedicels. |
in ample, leafy, paniculiform arrays, branches ascending, sometimes secund (heads often crowded). |
||||||||||||||||
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. |
dull purple or brown, obovoid, not compressed, 1.5–2 mm, 7–9-nerved, faces densely sericeous; pappi tan to tawny, sometimes rose to violet-tinged, 3.5–5.5 mm. |
||||||||||||||||
2n | = 10. |
|||||||||||||||||
Symphyotrichum lanceolatum |
Symphyotrichum ×amethystinum |
|||||||||||||||||
Phenology | Flowering Aug–Oct. | |||||||||||||||||
Habitat | Fields, prairies, disturbed grounds | |||||||||||||||||
Elevation | 200–400 m (700–1300 ft) | |||||||||||||||||
Distribution |
AL; AR; AZ; CA; CO; CT; DC; 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; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; ON; PE; QC; SK [Introduced in Europe]
|
CO; CT; IA; IL; IN; KY; MA; MD; MN; MO; ND; NE; NJ; NY; PA; RI; VT; WA; WI; ON |
||||||||||||||||
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. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Symphyotrichum ×amethystinum is the F1 hybrid between S. ericoides and S. novae-angliae, encountered sometimes throughout the area where the two parental species co-occur. It is morphologically intermediate; it has non-spiny, sparsely stipitate-glandular phyllaries and rose-violet rays in mid-sized heads. Forma leucerythros Bemis and forma leucos Bemis have been described within this hybrid and may represent recombinants or normal population color variants. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||
Key |
|
|||||||||||||||||
Source | FNA vol. 20. | FNA vol. 20, p. 497. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum | Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Aster lanceolatus | Aster amethystinus, Virgulus ×amethystinus | ||||||||||||||||
Name authority | (Willdenow) G. L. Nesom: Phytologia 77: 284. (1995) | (Nuttall) G. L. Nesom: Phytologia 77: 294. (1995) | ||||||||||||||||
Web links |
|