Symphyotrichum subulatum |
Symphyotrichum laurentianum |
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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 du golfe du saint-laurent, Gulf Of St. Lawrence aster |
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Habit | Annuals, (10–)30–150 cm; tap-rooted. | Annuals, 1–13+ cm. | ||||||||||||||||
Stems | 1, erect (often with purple or purplish brown areas), glabrous or glabrate, sometimes strigillose in leaf axils. |
1, decumbent to erect (straight), glabrous. |
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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. |
± fleshy, margins entire, eciliate, apices obtuse, faces glabrous; basal deciduous at bolting, petiolate, blades oblanceolate 44–50 × 5–7 mm [cult.], bases attenuate; proximal cauline and some distal withering by flowering; cauline sessile, blades linear-lanceolate to spatulate, 15–55 × 1–4 mm, reduced distally, bases cuneate; distal sessile, blades linear-lanceolate to spatulate. |
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Peduncles | (0.2–)0.5–4 cm, bracts 4–8(–17). |
glabrous, bracts linear. |
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Involucres | cylindric to turbinate, 5–7(–8.2) mm. |
campanulate, 5–8+mm. |
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Ray florets | 16–30(–54) in 1–3 series; corollas white, pink, or lavender, laminae 1.3–7 × 0.2–1.3 mm. |
0. |
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Pistillate florets | 14–47+ in 2–3+ series; laminae 0 (corolla tubes 2–2.4 mm, shorter than style branches). |
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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. |
5–8+; corollas yellow, 3.1–3.9 mm, lobes deltate to triangular, 0.2–0.3 mm. |
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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 3–4 series, lanceolate, subequal, bases scarious, margins eciliate, green zones foliaceous (outer), apices obtuse, faces glabrous. |
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Heads | (10–) 30–100(–150), in open, diffuse, paniculiform arrays. |
(disciform) in ± densely paniculiform arrays. |
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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. |
purple, obovoid, ± compressed, 2.8–2.9 mm, 2–4-nerved, faces strigillose; pappi white to yellowish white, 4.8–5.2 mm. |
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2n | = 14. |
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Symphyotrichum subulatum |
Symphyotrichum laurentianum |
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Phenology | Flowering Aug–Sep. | |||||||||||||||||
Habitat | Brackish sand and mud, intertidal salt marshes, moist dune slacks | |||||||||||||||||
Elevation | 0 m (0 ft) | |||||||||||||||||
Distribution |
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]
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NB; PE; QC |
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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.) |
Of conservation concern. Symphyotrichum laurentianum is known only from the southern shores of the Gulf of St. Lawrence. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 20, p. 480. | FNA vol. 20, p. 500. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium | Asteraceae > tribe Astereae > Symphyotrichum > subg. Symphyotrichum > sect. Conyzopsis | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Aster subulatus | Aster laurentianus, Aster laurentianus var. contiguus, Aster laurentianus var. magdalenensis | ||||||||||||||||
Name authority | (Michaux) G. L. Nesom: Phytologia 77: 293. (1995) | (Fernald) G. L. Nesom: Phytologia 77: 286. (1995) | ||||||||||||||||
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