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crooked-stem American-aster, crookedstem aster

Walter's aster

Habit Perennials, 20–90(–120) cm, colonial; long-rhizomatous. Perennials, 20–100 cm, colonial or cespitose, eglandular, sometimes sparsely, minutely stipitate-glandular; long-rhizomatous, with erect, thick, ± cormoid, woody caudices.
Stems

1(–3+), ascending to erect (usually flexuous, sometimes ± straight, sometimes stout, older often dark purple), glabrous proximally, moderately hirsute distally.

1–5+, erect to scandent-sprawling (mid to dark brown, branched from middle), glabrous or very sparsely fine strigose.

Leaves

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.

(bright green) thick, firm, ± succulent, margins entire;

basal early deciduous, sessile, blades (3-nerved) oblanceolate to obovate, 10–43 × 7–15 mm, bases cuneate, margins scabrous, apices obtuse, mucronate, faces sparsely finely scabrous;

proximal cauline sessile (patent to reflexed), blades ovate to lanceolate, 8–30 × 2–10 mm, bases cordate-clasping, apices acute, sometimes spinulose, faces finely scabrous, shiny;

distal sessile, blades lanceolate to triangular, 5–15 × 2.5–3.5 mm, reduced to bracts distally, bases clasping, margins finely scabrous, apices acute, white-spinulose, faces finely scabrous.

Peduncles

(8–)10–40 mm, sparsely to densely hispid, bracts lanceolate to linear-lanceolate, 3–12 mm, somewhat grading into phyllaries.

glabrous, bracts relatively numerous, tiny, foliaceous, becoming minute, linear, glabrous.

Involucres

campanulate, 5–6 mm.

campanulate, 5–7 mm.

Ray florets

17–25(–30);

corollas usually lavender to blue, rarely white, laminae 7.5–12(–15) × 1–2 mm.

11–26;

corollas bluish purple, laminae 5–9(–11) × 0.5–1 mm.

Disc florets

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.

(6–)15–25(–30);

corollas yellow, 4–6.5 mm, throats narrowly funnelform, lobes triangular, 0.4–0.8 mm.

Phyllaries

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.

in 4–5 series, oblanceolate, strongly unequal, bases (tan) ± indurate, margins hyaline, finely scabrous, green zones diamond-shaped, in distal 1/4–1/2, apices obtuse, mucronate to finely subspinulose, innermost acuminate, faces sparsely strigillose (often obscured by thick, shiny cuticle).

Heads

in broad, ± flat, corymbo-paniculiform arrays, branches often purplish, divaricate to ascending, slender.

borne singly in diffusely paniculiform arrays, branches initially patent to divaricate, elongate.

Cypselae

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.

tan to brown, obovoid, not compressed, 2–2.5 mm, nerves very faint, faces sparsely to moderately strigose;

pappi tan, 4–6 mm.

2n

= 32.

= 20.

Symphyotrichum prenanthoides

Symphyotrichum walteri

Phenology Flowering Aug–Oct. Flowering Oct–Dec.
Habitat Moist or swampy grounds, woods, thickets, meadows, seeps, stream banks, roadsides Sandy, clayey soils, margins of woods, open oak-pine scrub, pine flatwoods, fields, roadsides
Elevation 100–1500 m (300–4900 ft) 0–100+ m (0–300+ ft)
Distribution
from FNA
CT; DC; DE; IA; IL; IN; KY; MA; MD; MI; MN; NC; NJ; NY; OH; PA; VA; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; GA; NC; SC
[WildflowerSearch map]
[BONAP county map]
Discussion

Symphyotrichum prenanthoides is of conservation concern in Canada and in a number of states.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 20, p. 527. FNA vol. 20, p. 492.
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. 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
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. 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. welshii, S. yukonense, S. ×amethystinum
Synonyms Aster prenanthoides Aster walteri, Lasallea walteri, Virgulus walteri
Name authority (Muhlenberg ex Willdenow) G. L. Nesom: Phytologia 77: 290. (1995) (Alexander) G. L. Nesom: Phytologia 77: 294. (1995)
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