Symphyotrichum tenuifolium
Symphyotrichum ×amethystinum
perennial saltmarsh American-aster, perennial saltmarsh aster
amethyst aster, aster, hybrid aster
1–5+, ascending to erect (often with purple or purplish brown areas, flexuous, wiry), little-branched, usually glabrous, sometimes hairy in lines distally.
1–5+, erect (light brown to grayish brown), densely hispidulo-hirsute.
thick (fleshy), margins entire, faces glabrous;
basal withering by flowering (new winter rosettes appearing at flowering), petiolate (petioles sheathing), blades ovate or oblanceolate, 15–20 × 5–15 mm, bases cuneate, apices rounded;
proximal cauline withering by flowering, usually sessile, blades lanceolate, linear-lanceolate or -oblanceolate, to linear, 7–80(–150) × 1–6 (–12) mm, bases attenuate, margins entire, apices acuminate to acute;
distal sessile, blades narrowly lanceolate to subulate, 10–110 × 0.5–5 mm, apices acuminate.
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.
0.6–4 (–6) cm, bracts 2–8, awl-shaped, grading into phyllaries.
hispid, bracts 1–3+, oblong-lanceolate, 3–5 mm, not grading into phyllaries.
narrowly turbinate, 4.1–9.5(–11) mm.
campanulate to hemispheric, 4–6 mm.
10–25;
corollas white or pink, laminae (4.5–)5–8.5(–9.5) × 1.2–2 mm.
20–35;
corollas azure blue to violet or lavender, laminae 5–10 × 0.6–1.2 mm.
25–45(–54);
corollas yellow becoming purplish, 3.4–6(–6.8) mm, tubes shorter than to equaling the narrowly funnelform throats (sparsely hairy at base), lobes ± erect, narrowly triangular, 0.5–0.8 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.
in 4–5 series, lanceolate to subulate, bases indurate, rounded, margins hyaline, often tinged with purple, entire, green zones spatulate to oblanceolate-rhombic, apices acute, adaxial faces glabrous or minutely hairy distally.
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.
(1–)3–20(–40), in open, diffuse, paniculiform arrays, branches patent.
in ample, leafy, paniculiform arrays, branches ascending, sometimes secund (heads often crowded).
light brown, narrowly obovoid to fusiform, sometimes ± compressed, 1.5–4(–4.5) mm, 5–6-nerved, faces sparsely strigillose;
pappi tawny to white, 3–6.1 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.
= 10.
Symphyotrichum tenuifolium
Symphyotrichum ×amethystinum
Varieties 2 (2 in the flora).
Along the Gulf of Mexico Coast in central and northern peninsular Florida, vars. tenuifolium and aphyllum intergrade in nearly all characters (S. D. Sundberg 2004). G. L. Nesom (2005d) treated the varieties as 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.)
1. Stems 1, rhizomes long; mid leaves (1.5–)3–6 mm wide; involucres 6–9.5(–11) mm; ray florets (12–)17–25; disc florets 25–45(–54), corollas (4–)4.7–6(–6.5) mm; cypselae 2.8–4(–4.5) mm; pappi 5–6.1 mm | var. tenuifolium |
1. Stems 1–5+ (clustered), rhizomes short; mid leaves (1–)1.5–2.7 mm wide; involucres 4.1–5.3 mm; ray florets 10–16; disc florets (10–)13–23, corollas 3.4–4.6 mm; cypselae 1.5–2(–2.5) mm; pappi 3–4.4 mm | var. aphyllum |
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