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rigid whitetop aster

thin-leaf late purple aster

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

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
from FNA
AL; GA; NC; SC; TN; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; CT; DC; DE; GA; IN; KY; MA; MD; NC; NY; OH; PA; RI; SC; TN; VA; WV
[WildflowerSearch map]
[BONAP county map]
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.)

Source FNA vol. 20, p. 510. FNA vol. 20, p. 490.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus
Sibling taxa
S. adnatum, S. anomalum, S. anticostense, S. ascendens, S. boreale, S. bracteolatum, S. campestre, S. chapmanii, S. chilense, S. ciliatum, S. ciliolatum, S. concolor, S. cordifolium, S. cusickii, S. defoliatum, S. depauperatum, S. drummondii, S. dumosum, S. elliottii, S. ericoides, S. eulae, S. falcatum, S. fendleri, S. firmum, S. foliaceum, S. fontinale, S. frondosum, S. georgianum, S. grandiflorum, S. greatae, S. hallii, S. hendersonii, S. jessicae, S. laeve, S. lanceolatum, S. lateriflorum, S. laurentianum, S. lentum, S. molle, S. nahanniense, S. novae-angliae, S. novi-belgii, S. oblongifolium, S. ontarionis, S. oolentangiense, S. parviceps, S. patens, S. phlogifolium, S. pilosum, S. plumosum, S. porteri, S. potosinum, S. praealtum, S. pratense, S. prenanthoides, S. priceae, S. puniceum, S. pygmaeum, S. racemosum, S. rhiannon, S. robynsianum, S. sericeum, S. shortii, S. simmondsii, S. spathulatum, S. subspicatum, S. subulatum, S. tenuifolium, S. tradescantii, S. turbinellum, S. undulatum, S. urophyllum, S. walteri, S. welshii, S. yukonense, S. ×amethystinum
S. adnatum, S. anomalum, S. anticostense, S. ascendens, S. boreale, S. bracteolatum, S. campestre, S. chapmanii, S. chilense, S. ciliatum, S. ciliolatum, S. concolor, S. cordifolium, S. cusickii, S. defoliatum, S. depauperatum, S. drummondii, S. dumosum, S. elliottii, S. ericoides, S. eulae, S. falcatum, S. fendleri, S. firmum, S. foliaceum, S. fontinale, S. frondosum, S. georgianum, S. grandiflorum, S. greatae, S. hallii, S. hendersonii, S. jessicae, S. laeve, S. lanceolatum, S. lateriflorum, S. laurentianum, S. lentum, S. molle, S. nahanniense, S. novae-angliae, S. novi-belgii, S. oblongifolium, S. ontarionis, S. oolentangiense, S. parviceps, S. patens, S. pilosum, S. plumosum, S. porteri, S. potosinum, S. praealtum, S. pratense, S. prenanthoides, S. priceae, S. puniceum, S. pygmaeum, S. racemosum, S. retroflexum, S. rhiannon, S. robynsianum, S. sericeum, S. shortii, S. simmondsii, S. spathulatum, S. subspicatum, S. subulatum, S. tenuifolium, S. tradescantii, S. turbinellum, S. undulatum, S. urophyllum, S. walteri, S. welshii, S. yukonense, S. ×amethystinum
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)
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