Symphyotrichum tenuifolium
Symphyotrichum prenanthoides
perennial saltmarsh American-aster, perennial saltmarsh aster
crooked-stem American-aster, crookedstem 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(–3+), ascending to erect (usually flexuous, sometimes ± straight, sometimes stout, older often dark purple), glabrous proximally, moderately hirsute distally.
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.
thin, margins scabrous, apices mucronate, abaxial faces glabrous, midveins hispid to glabrate, adaxial scabrous;
basal withering by flowering, petiolate (petioles slender or slightly winged, bases reddish, dilated, sheathing, ciliate), blades obovate to oblanceolate, 15–70 × 10–20 mm, bases attenuate, margins crenate-serrate, apices acute to obtuse;
proximalmost cauline withering by flowering, proximal mostly persistent, petiolate to subpetiolate (petioles ± widely winged, bases dilated, strongly auriculate-clasping), blades ovate to lance-ovate or elliptic-lanceolate to oblanceolate, 80–160(–200) × 15–55 mm, progressively reduced distally, bases attenuate, margins sharply serrate (teeth mucronulate), apices acuminate to subcaudate;
distal subpetiolate or sessile (petioles broadly winged, auriculate-clasping), blades oblanceolate to lanceolate, sometimes panduriform, 7–90 × 2–25 mm, progressively reduced distally, more sharply so on branches, bases attenuate (petiolate) or ± cuneate to auriculate-clasping and slightly constricted above auricles (panduriform), margins serrate or entire.
0.6–4 (–6) cm, bracts 2–8, awl-shaped, grading into phyllaries.
(8–)10–40 mm, sparsely to densely hispid, bracts lanceolate to linear-lanceolate, 3–12 mm, somewhat grading into phyllaries.
narrowly turbinate, 4.1–9.5(–11) mm.
campanulate, 5–6 mm.
10–25;
corollas white or pink, laminae (4.5–)5–8.5(–9.5) × 1.2–2 mm.
17–25(–30);
corollas usually lavender to blue, rarely white, laminae 7.5–12(–15) × 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.
39–50(–65);
corollas cream colored or light yellow becoming purple or brown, 3.5–5 mm, tubes ± equaling campanulate to funnelform throats (thinly puberulent), lobes triangular, 0.5–1 mm.
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 4–6 series, oblong-lanceolate or -oblanceolate, slightly constricted near middle (outer) to linear-lanceolate or linear (inner), ± unequal (flexible), bases indurate 1/5–1/2, margins ± narrowly hyaline, scarious, erose, sometimes ciliolate distally, green zones lanceolate to linear-lanceolate (inner), often distally foliaceous, sometimes outer ± entirely so, apices spreading to ± squarrose, acute to acuminate, mucronulate, abaxial faces sparsely hirsutulous to glabrate or glabrous, adaxial glabrous or sparsely hirsutulous.
(1–)3–20(–40), in open, diffuse, paniculiform arrays, branches patent.
in broad, ± flat, corymbo-paniculiform arrays, branches often purplish, divaricate to ascending, slender.
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 stramineous with purple streaks or purplish-tinged, cylindro-oblanceoloid to obovoid, ± compressed, 2–3(–3.5) mm, 4–6-nerved, faces sparsely to moderately strigillose;
pappi sordid, 3.5–4.5 mm.
= 32.
Symphyotrichum tenuifolium
Symphyotrichum prenanthoides
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 prenanthoides is of conservation concern in Canada and in a number of states.
(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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