Symphyotrichum ×amethystinum |
Symphyotrichum fendleri |
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amethyst aster, aster, hybrid aster |
Fendler's aster |
|
Habit | Perennials, cespitose, 30–120 cm; with thick, woody, short-branched caudices at ends of fleshy rhizomes. | Perennials, 6–30 cm, cespitose; with thick, woody, branched caudices. |
Stems | 1–5+, erect (light brown to grayish brown), densely hispidulo-hirsute. |
1–10+, decumbent to ascending or erect (grayish brown, slender), sparsely strigoso-hispid, ± scabrous. |
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. |
(dark bright green) firm, much reduced distally, margins entire, apices acute, mucronate, faces usually glabrous, sometimes sparsely strigoso-hispid; basal withering by flowering (new vernal rosettes often present), sessile, blades (1–3-nerved) linear-oblanceolate, 20–40 × 5–30 mm, bases attenuate, margins scabro-ciliate; proximal cauline sometimes persistent, sessile, blades linear to linear-lanceolate, 10–40 × 5–20 mm, bases sometimes subclasping, margins entire, scabrous; distal sessile, blades linear to linear-lanceolate, 20–40 × 2–3 mm, bases cuneate, margins entire, coarsely cililate-spinulose, apices acute, white-spinulose, faces sometimes stipitate-glandular. |
Peduncles | hispid, bracts 1–3+, oblong-lanceolate, 3–5 mm, not grading into phyllaries. |
sparsely hispido-strigose, ± densely stipitate-glandular, bracts ± ascending, linear to lance-oblong, grading into phyllaries. |
Involucres | campanulate to hemispheric, 4–6 mm. |
campanulate, 4–7 mm. |
Ray florets | 20–35; corollas azure blue to violet or lavender, laminae 5–10 × 0.6–1.2 mm. |
10–20; corollas light to dark lavender to purple, laminae 5–10 × 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. |
(7–)10–30; corollas yellow becoming reddish purple, 3.5–5 mm, throats narrowly funnelform, lobes narrowly triangular, 0.4–0.7 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, lanceolate, unequal, bases ± indurate, margins narrowly to widely scarious, hyaline except apically, sometimes ciliolate, often stipitate-glandular, green zones lanceolate to diamond-shaped, covering distal portion (outer), apices acuminate, spreading to reflexed, faces glabrous, moderately to densely short-stipitate-glandular. |
Heads | in ample, leafy, paniculiform arrays, branches ascending, sometimes secund (heads often crowded). |
in ± narrowly racemiform to paniculiform arrays, branches sometimes initially patent, then spreading to 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. |
brown (nerves stramineous), obovoid, ± compressed, 1.5–2.5 mm, 7–10-nerved, faces moderately strigillose; pappi cinnamon to sordid, sometimes purplish-tinged, 4.5–5 mm. |
2n | = 10. |
= 10. |
Symphyotrichum ×amethystinum |
Symphyotrichum fendleri |
|
Phenology | Flowering Aug–Oct. | Flowering (Aug–)Sep–Oct. |
Habitat | Fields, prairies, disturbed grounds | Open, sandy, silty, shaly, often rocky soils, eroded limestone or sandstone outcrops, mixed-grass prairies, pastures, roadsides |
Elevation | 200–400 m (700–1300 ft) | 600–2000 m (2000–6600 ft) |
Distribution |
CO; CT; IA; IL; IN; KY; MA; MD; MN; MO; ND; NE; NJ; NY; PA; RI; VT; WA; WI; ON |
CO; KS; NE; NM; OK; TX
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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.) |
Symphyotrichum fendleri has been reported from Mexico (Chihuahua) [by C. H. Schultz-Bipontinus (1856) fide G. L. Nesom (pers. comm.)], but its occurrence in Mexico remains to be confirmed. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 497. | FNA vol. 20, p. 486. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Aster amethystinus, Virgulus ×amethystinus | Aster fendleri, Virgulus fendleri |
Name authority | (Nuttall) G. L. Nesom: Phytologia 77: 294. (1995) | (A. Gray) G. L. Nesom: Phytologia 77: 282. (1995) |
Web links |