Symphyotrichum retroflexum |
Symphyotrichum phlogifolium |
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rigid whitetop aster |
thin-leaf late purple aster |
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Habit | Perennials, 40–100 cm, usually colonial, sometimes ± cespitose; short-(seldom long-)rhizomatous. | Perennials, 50–130 cm, cespitose; with short, thick, woody caudices, not rhizomatous. |
Stems | 1–2+, erect (straight to slightly flexuous, sometimes robust), glabrous. |
1, erect to arching, light to dark brown, soft-hairy, hairs ascending- to spreading- stipitate-glandular distally. |
Leaves | thin to firm, margins slightly recurved, scabrous, faces glabrous; basal mostly withering by flowering, petiolate (petioles narrowly winged, sheathing), blades lanceolate-ovate to ovate or spatulate, 25–110 × 10–40 mm, bases usually rounded to attenuate, seldom ± cordate, margins serrulate to shallowly serrate, apices obtuse to acute; proximal cauline often withering by flowering, petiolate (petioles ± widely winged, ± clasping), blades lance-ovate or narrowly ovate, 50–95 × 19–31 mm, bases usually rounded to attenuate, sometimes cuneate, rarely subcordate, margins serrate to serrulate; distal winged-petiolate or subpetiolate or sessile, blades lance-ovate or narrowly ovate to lanceolate or sometimes linear (in arrays), 7–1.5 × 3–31 mm, gradually and strongly reduced distally, bases cuneate, scarcely or not clasping, to slightly rounded and ± clasping, margins serrulate or entire, apices acute to acuminate. |
(dark green) thin, almost membraneous; basal early deciduous, sessile or subpetiolate, blades spatulate to obovate, 80–140 × 20–30 mm, bases cuneate, margins entire to ± serrate, scabrous, apices acute; proximal cauline withering by flowering, sessile, blades panduriform, (20–)30–70(–110) × 10–30(–35) mm, bases auriculate-clasping, margins entire (flat), sparsely villoso-ciliate, apices acute, faces finely sparely villous or scabrous, stipitate-glandular; distal sessile, blades (rugose-veined when fresh) ovate to lanceolate, 75–125(–140) × 15–35(–40) mm, bases strongly cordate-clasping to auriculate-amplexicaul, margins entire (± undulate), apices acute, acuminate to merely mucronate, faces sparsely strigose, moderately so along veins, sparsely to moderately stipitate-glandular. |
Peduncles | (when present) 0.2–1.5 cm, densely pilose or pilosulous, bracts 1–6+, lanceolate to oblong-lanceolate, foliaceous to distally grading into phyllaries. |
short (less than 4 cm), strigose, stipitate-glandular, bracts linear-lanceolate, ascending-appressed, grading into phyllaries. |
Involucres | campanulate, (6–)7–10 mm. |
cylindric, 5.5–7.5(–8) mm. |
Ray florets | 13–30; corollas blue to purple, laminae (10–)15–17 × 1.6–3 mm. |
9–17; corollas light to dark reddish purple, laminae 10–18(–20) × 1–3 mm. |
Disc florets | 35–50+; corollas cream to pale yellow becoming pinkish, 5.8–6.8 mm, tubes shorter than funnelform throats, lobes lanceolate, 0.9–1.2 mm, glabrous. |
15–35; corollas white with purple lobes, 6–8 mm, lobes triangular, 1–1.5 mm. |
Phyllaries | in 3–4(–5) series, broadly lanceolate constricted to narrow oblong bases (outer) to oblong-lanceolate or linear-lanceolate (inner), ± unequal, bases indurate 1/10–1/5 (outer) to 4/5+ (inner), margins hyaline, narrowly scarious, erose (indurate portion), sparsely ciliolate (foliaceous portion), green zones foliaceous (outer) to distal 1/5–1/4 foliaceous (inner), basally truncate to lanceolate, apices spreading to squarrose, acute to acuminate, mucronulate, abaxial faces glabrous or glabrate, adaxial strigillose (foliaceous portion). |
in 4–6 series, linear-lanceolate, unequal, bases (tan) ± indurate in proximal 1/3–1/2, margins hyaline, erose, distally scabro-ciliolate to ciliolate, green zones covering distal 1/2, apices outer obtuse to acute, inner acuminate, purplish, faces sparsely strigillose, usually moderately to densely stipitate-glandular, rarely sparsely so. |
Heads | in broad (appearing ± corymbiform) or narrow, paniculiform to ± racemiform arrays, branches usually long (to 10 cm), ascending to divaricate. |
in crowded, paniculiform arrays, branches often initially patent then ascending. |
Cypselae | tan, obovoid to oblanceoloid, compressed, 3–3.9 mm, 4–6-nerved, faces glabrous or sparsely strigillose; pappi whitish to reddish, 5.3–6 mm. |
dark brown to black, obovoid, not compressed, 2.5–4 mm, 7–10-nerved, faces densely strigose along ribs; pappi tan to tawny, sometimes slightly purplish-tinged, 6–8 mm. |
2n | = 48. |
= 20. |
Symphyotrichum retroflexum |
Symphyotrichum phlogifolium |
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Phenology | Flowering Aug–Oct. | Flowering Aug–Oct. |
Habitat | Moist meadows, moist woodlands, dry, open, pine or oak woods, wooded roadsides | Loamy, sandy, or gravelly soils, rich mesic mixed-hardwood forests (Appalachians), roadsides |
Elevation | 400–1500 m (1300–4900 ft) | 0–1100 m (0–3600 ft) |
Distribution |
AL; GA; NC; SC; TN; VA
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AL; CT; DC; DE; GA; IN; KY; MA; MD; NC; NY; OH; PA; RI; SC; TN; VA; WV
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Discussion | Symphyotrichum retroflexum is known only from the Appalachian Blue Ridges. It is possible that the species is an allopolyploid derived from members of subsections Cordifolii and Symphyotrichum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 20, p. 510. | FNA vol. 20, p. 490. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Aster retroflexus, Aster curtisii | Aster phlogifolius, Aster patens var. phlogifolius, Virgulus patens var. phlogifolius |
Name authority | (Lindley ex de Candolle) G. L. Nesom: Phytologia 77: 291. (1995) | (Muhlenberg ex Willdenow) G. L. Nesom: Phytologia 77: 289. (1995) |
Web links |