Symphyotrichum ×amethystinum |
Symphyotrichum campestre |
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amethyst aster, aster, hybrid aster |
meadow aster, western meadow aster |
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Habit | Perennials, cespitose, 30–120 cm; with thick, woody, short-branched caudices at ends of fleshy rhizomes. | Perennials, 10–40 cm, colonial or cespitose; long-rhizomatous. |
Stems | 1–5+, erect (light brown to grayish brown), densely hispidulo-hirsute. |
1–5+, ascending to erect (light to dark brown), proximally glabrous, distally strigose, stipitate-glandular. |
Leaves | 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. |
(light green) firm, margins entire, scabrous; basal sometimes persistent, sessile, blades (1–3-nerved) linear-oblanceolate, 10–30 × 4–10 mm, bases attenuate, apices obtuse, mucronate, faces glabrate to sparsely scabrous; proximal cauline withering by flowering, sessile, blades (3-nerved) narrowly oblanceolate, 20–80 × 2–8 mm, bases cuneate, apices obtuse to acute, mucronulate or white-spinulose, faces glabrous or moderately short-strigose, stipitate-glandular; distal sessile, blades linear-oblanceolate to -lanceolate or oblong (distally), 20–50 × 2–5 mm, ± reduced distally, bases ± clasping to cuneate, apices acute, mucronulate, faces glabrous or moderately short-strigose, stipitate-glandular. |
Peduncles | hispid, bracts 1–3+, oblong-lanceolate, 3–5 mm, not grading into phyllaries. |
sparsely to moderately short-strigose, moderately stipitate-glandular, bracts ± ascending, linear to narrowly-lanceolate. |
Involucres | campanulate to hemispheric, 4–6 mm. |
campanulate to cylindro-campanulate, 5.5–8 mm. |
Ray florets | 20–35; corollas azure blue to violet or lavender, laminae 5–10 × 0.6–1.2 mm. |
15–31; corollas violet, laminae (5–)6–15 × 1–2 mm. |
Disc florets | 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. |
25–40; corollas yellow, 4.5–6 mm, lobes triangular, 0.4–0.8 mm. |
Phyllaries | 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. |
in 3–4 series, linear to lanceolate, subequal to unequal, bases ± indurate, margins scarious, green zones covering distal portion, apices acute to acuminate, outer ± foliaceous, spreading to reflexed, faces glabrate, sparsely to densely stipitate-glandular. |
Heads | in ample, leafy, paniculiform arrays, branches ascending, sometimes secund (heads often crowded). |
1–10(–30), borne singly or in paniculiform arrays, branches ascending. |
Cypselae | 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. |
light brown, sometimes translucent reddish brown between ribs, narrowly obovoid, ± compressed, 2–2.5 mm, 3–4-nerved (faint), moderately strigose on ribs; pappi tawny, 3.8–6 mm. |
2n | = 10. |
= 10. |
Symphyotrichum ×amethystinum |
Symphyotrichum campestre |
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Phenology | Flowering Aug–Oct. | Flowering Aug–Oct. |
Habitat | Fields, prairies, disturbed grounds | Open, often dry, disturbed, rocky and sandy soils near ponds and streams, dry grass meadows, open pine-douglas fir forests, plains to montane zones |
Elevation | 200–400 m (700–1300 ft) | 1500–2500 m (4900–8200 ft) |
Distribution |
CO; CT; IA; IL; IN; KY; MA; MD; MN; MO; ND; NE; NJ; NY; PA; RI; VT; WA; WI; ON |
CA; CO; ID; MT; NV; OR; WA; WY; AB; BC
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Discussion | 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.) |
Two poorly defined varieties of Symphyotrichum campestre have been described. Variety campestre has glabrous or sparsely strigose leaves and occurs in southern British Columbia, Colorado, Idaho, Montana, Nevada, Oregon, Washington, and Wyoming. Bloomer’s Aster, var. bloomeri, has moderately strigose leaves and occurs in California, Nevada, and Oregon. The varieties are not sufficiently distinct to warrant recognition. Symphyotrichum ×columbianum (Piper) G. L. Nesom (syn. Aster columbianus Piper, A. multiflorus Aiton var. columbianus (Piper) S. F. Blake, Virgulus ×columbianus (Piper) Reveal & Keener) is the hybrid between S. campestre and S. ericoides subsp. pansum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 497. | FNA vol. 20, p. 484. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Aster amethystinus, Virgulus ×amethystinus | Aster campestris, Aster bloomeri, Aster campestris var. bloomeri, S. campestre var. bloomeri, Virgulus campestris |
Name authority | (Nuttall) G. L. Nesom: Phytologia 77: 294. (1995) | (Nuttall) G. L. Nesom: Phytologia 77: 276. (1995) |
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