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annual saltmarsh American-aster, annual saltmarsh aster, annual saltmarsh or eastern annual saltmarsh aster, aster subulé, eastern annual saltmarsh aster, Southwestern annual saltmarsh aster

aster poilu, awl American-aster, frost aster, hairy aster, hairy white Oldfield aster, Oldfield or frost weed or white Oldfield or hairy or hairy white Oldfield aster, white heath aster

Habit Annuals, (10–)30–150 cm; tap-rooted. Perennials cespitose, (5–)20–120(–150+) cm; with stout, branched caudices, sometimes long-rhizomatous.
Stems

1, erect (often with purple or purplish brown areas), glabrous or glabrate, sometimes strigillose in leaf axils.

1–5+, ascending to erect (straight, stout), glabrate to hirsuto-hispid or pilose, sometimes glabrous or hairy in lines (var. pringlei).

Leaves

thin (green to dark green), margins often strigilloso-ciliolate, faces glabrous;

basal withering by flowering, long-petiolate (petiole bases sheathing), sparsely ciliate, blades ovate to oblanceolate, 10–90 × 6–14 mm, bases attenuate to cuneate, rounded, margins entire or serrulate or crenulate, apices rounded, obtuse, or acute;

proximal cauline withering by flowering, petiolate, subpetiolate, or sessile, blades narrowly lanceolate or subulate, 20–100(–200) × 1.5–10(–20) mm, bases attenuate, margins subentire, entire, or serrulate, apices acute to acuminate;

distal sessile, blades narrowly lanceolate to subulate, 5–113 × 0.5–5.5 mm, apices acuminate.

thin, margins ciliate, apices acute to acuminate, mucronate, faces glabrous or ± hirsute (particularly on abaxial midveins);

basal withering by flowering (new vernal rosettes developing at flowering), petiolate to subpetiolate (petioles winged, ciliate, bases sheathing), blades oblanceolate or obovate to spatulate, 10–60 × 5–15 mm, bases attenuate, margins sparsely crenate-serrate (mostly apically), apices obtuse to rounded;

proximal cauline usually deciduous at flowering (often with axillary clusters of small leaves), petiolate or subpetiolate to subsessile (petioles narrowly to broadly winged, clasping), blades elliptic-oblanceolate or -oblong to linear-lanceolate or -oblanceolate, 40–102 × 5–25 mm, progressively reduced distally, bases attenuate to cuneate, ± clasping, margins entire to serrate, softly ciliate, apices attenuate, hyaline-spinulose;

distal sessile, blades lance-oblong to linear-lanceolate to linear or linear-oblanceolate or linear-subulate, 10–100 × 1–8 mm, progressively reduced distally, branch leaves abruptly smaller, bases cuneate, margins entire or serrulate.

Peduncles

(0.2–)0.5–4 cm, bracts 4–8(–17).

5–30(–50) mm, progressively shorter distally, glabrous or densely hispid, bracts 7–25+, appressed to ascending, sometimes ± spreading, linear to subulate, glabrate, ciliate or not, mucronate to apiculate, ± grading into phyllaries.

Involucres

cylindric to turbinate, 5–7(–8.2) mm.

campanulate to cylindro-campanulate, (2.5–)3.5–5.1(–6.5) mm.

Ray florets

16–30(–54) in 1–3 series;

corollas white, pink, or lavender, laminae 1.3–7 × 0.2–1.3 mm.

(10–)16–28(–38);

corollas usually white, rarely pinkish or bluish, laminae (4–)5.4–7.5(–11) × (0.4–)0.8–1.3(–1.7) mm.

Disc florets

4–10(–13);

corollas yello, sometimes tinged with purple, 3.4–5.2 mm, throats narrowly funnelform, lobes ± spreading to erect, narrowly triangular, 0.3–0.7 mm, glabrous.

(13–)17–39(–67);

corollas light yellow becoming reddish purple or brown, (2.5–)3–4.1(–5.5) mm, tubes much shorter than narrowly funnelform throats, lobes lanceolate, (0.4–)0.6–0.8(–1) mm.

Phyllaries

in 3–5 series, broadly or narrowly lanceolate to subulate, unequal, bases indurate, margins hyaline, often purple-tinged, entire, green zones lanceolate (usually narrow, sometimes broad and covering most of distal portion), apices acute, faces glabrous.

in 4–6 series, appressed or slightly spreading, oblong-lanceolate (outer) to linear (innermost) , unequal (rarely subequal), bases indurate 1/2–3/5, margins hyaline, scarious, erose, ± ciliolate distally, green zones lanceolate to lance-rhombic, apices acute or acuminate, involute, spinulose, faces glabrous or sparsely hirsutulous.

Heads

(10–) 30–100(–150), in open, diffuse, paniculiform arrays.

in open, leafy, often pyramidal, paniculiform arrays, branches divaricate or branches 10 cm or less ascending, often arched and secund, sometimes racemiform.

Cypselae

light brown to purple, narrowly obovoid to fusiform, sometimes ± compressed, (1.2–)1.5–2.7(–3) mm, 5-nerved, faces sparsely strigillose;

pappi white, (3–)3.5–5.5 mm.

whitish or gray, oblong-obovoid, sometimes ± compressed, 1–1.5 × 0.5–0.7 mm, 4–6-nerved, faces sparsely strigillose;

pappi white, 3.5–4 mm.

Symphyotrichum subulatum

Symphyotrichum pilosum

Distribution
from FNA
AL; AR; AZ; CA; CT; DE; FL; GA; IL; IN; KS; LA; MA; MD; ME; MI; MS; NC; NE; NH; NJ; NM; NV; NY; OH; OK; PA; RI; SC; TN; TX; UT; VA; NB; ON; Mexico; Central America; South America; West Indies; Bermuda [Widely introduced worldwide]
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; SD; TN; VA; VT; WI; WV; BC; NB; NS; ON; QC
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 5 (5 in the flora).

Five varieties of Symphyotrichum subulatum are recognized for North America based on differences in chromosome number, ray lamina color and size, array shapes, number of series of ray florets, number of disc and ray florets, and other, more cryptic characters (S. D. Sundberg 2004). These varieties were treated as species by G. L. Nesom (1994b, 2005d). Variety ligulatum is apparently an obligate outcrosser and is the least variable variety (Sundberg). Other varieties are self-compatible, which could facilitate the fixation of mutations in populations.

The five varieties are nearly entirely allopatric, and intermediates between pairs of varieties are not uncommon where they approach one another. Populations that are intermediate in ray lamina size between vars. ligulatum and parviflorum are widespread in southern Texas, New Mexico, Arizona, and northern Mexico. Intermediates between vars. elongatum and parviflorum and between vars. elongatum and subulatum occur in Florida. Despite these observations, hybridization experiments and chromosome number differences suggest that the varieties are mostly reproductively isolated (S. D. Sundberg 1986, 2004).

In older floras the name Aster exilis Elliott has been applied to Symphyotrichum subulatum vars. ligulatum and parviflorum. The status of this name is uncertain; the type specimen has been lost and the description of the plant is inadequate for determining the taxon to which the name should be applied (G. L. Nesom 1994b; S. D. Sundberg 2004).

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

Varieties 2 (2 in the flora).

The ecology and cytogeography of Symphyotrichum pilosum were summarized by J. G. Chmielewski and J. C. Semple (2001b). The species is often confused with S. ericoides, which inhabits the same kinds of open, prairie-like habitats; the latter can be distinguished by its smaller heads and spine-tipped phyllary apices. Because of that, the name Aster ericoides has been misapplied often in floras and in the horticultural trade.

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

Key
1. Ray laminae lavender to blue, (3.5–)4.5–7 × 0.9–1.3 mm, drying in 3–5 coils; ray florets in 1 series; disc florets (20–)33–50 (sc United States)
var. ligulatum
1. Ray laminae white to pink or lavender, 1.3–3.5(–4.2) × 0.2–0.6 mm, drying in (0–)1–3(–4) coils; ray florets in 1–3 series; disc florets 3–23
→ 2
2. Ray laminae pink to lavender, (2–)2.5–3.5(–4.2) × 0.3–0.6 mm, drying in 2–3(–4) coils; disc florets 11–23 (Florida, West Indies)
var. elongatum
2. Ray laminae usually white, rarely pink or lavender, 1.3–3 × 0.2–0.5 mm, drying in 1 coil or curling; disc florets (3–)4–15
→ 3
3. Ray laminae longer than pappi; phyllaries 30–42; pappi 3.5–3.8(–4.2) mm; w United States
var. parviflorum
3. Ray laminae shorter to slightly longer than pappi; phyllaries 18–30; pappi 3.5–5.5 mm; e and se United States
→ 4
4. Green zones of phyllaries narrowly to broadly lanceolate, extending phyllary length; ray laminae 0.2–0.5 mm wide; disc florets 3.8–4.6(–4.9) mm; salt marshes, e North America and Gulf Coast
var. subulatum
4. Green zones of phyllaries broadly lanceolate, nearly absent from proximal portion; ray laminae 0.2–0.3 mm wide; disc florets 3.2–4.1 mm; adventive, s United States
var. squamatum
1. Stems sparsely to densely hirsute; leaves pilose; various substrates
var. pilosum
1. Stems glabrous; leaves glabrous or glabrate; mainly on calcareous substrates
var. pringlei
Source FNA vol. 20, p. 480. FNA vol. 20, p. 511.
Parent taxa Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Symphyotrichum
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. retroflexum, S. rhiannon, S. robynsianum, S. sericeum, S. shortii, S. simmondsii, S. spathulatum, S. subspicatum, 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. 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
Subordinate taxa
S. subulatum var. elongatum, S. subulatum var. ligulatum, S. subulatum var. parviflorum, S. subulatum var. squamatum, S. subulatum var. subulatum
S. pilosum var. pilosum, S. pilosum var. pringlei
Synonyms Aster subulatus Aster pilosus, Aster ericoides var. pilosus
Name authority (Michaux) G. L. Nesom: Phytologia 77: 293. (1995) (Willdenow) G. L. Nesom: Phytologia 77: 289. (1995)
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