Symphyotrichum subulatum |
Symphyotrichum walteri |
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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 |
Walter's aster |
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Habit | Annuals, (10–)30–150 cm; tap-rooted. | Perennials, 20–100 cm, colonial or cespitose, eglandular, sometimes sparsely, minutely stipitate-glandular; long-rhizomatous, with erect, thick, ± cormoid, woody caudices. | ||||||||||||||||
Stems | 1, erect (often with purple or purplish brown areas), glabrous or glabrate, sometimes strigillose in leaf axils. |
1–5+, erect to scandent-sprawling (mid to dark brown, branched from middle), glabrous or very sparsely fine strigose. |
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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. |
(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. |
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Peduncles | (0.2–)0.5–4 cm, bracts 4–8(–17). |
glabrous, bracts relatively numerous, tiny, foliaceous, becoming minute, linear, glabrous. |
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Involucres | cylindric to turbinate, 5–7(–8.2) mm. |
campanulate, 5–7 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. |
11–26; corollas bluish purple, laminae 5–9(–11) × 0.5–1 mm. |
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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. |
(6–)15–25(–30); corollas yellow, 4–6.5 mm, throats narrowly funnelform, lobes triangular, 0.4–0.8 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 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). |
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Heads | (10–) 30–100(–150), in open, diffuse, paniculiform arrays. |
borne singly in diffusely paniculiform arrays, branches initially patent to divaricate, elongate. |
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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. |
tan to brown, obovoid, not compressed, 2–2.5 mm, nerves very faint, faces sparsely to moderately strigose; pappi tan, 4–6 mm. |
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2n | = 20. |
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Symphyotrichum subulatum |
Symphyotrichum walteri |
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Phenology | Flowering Oct–Dec. | |||||||||||||||||
Habitat | Sandy, clayey soils, margins of woods, open oak-pine scrub, pine flatwoods, fields, roadsides | |||||||||||||||||
Elevation | 0–100+ m (0–300+ 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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FL; GA; NC; SC
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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.) |
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Key |
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Source | FNA vol. 20, p. 480. | FNA vol. 20, p. 492. | ||||||||||||||||
Parent taxa | Asteraceae > tribe Astereae > Symphyotrichum > subg. Astropolium | Asteraceae > tribe Astereae > Symphyotrichum > subg. Virgulus | ||||||||||||||||
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Synonyms | Aster subulatus | Aster walteri, Lasallea walteri, Virgulus walteri | ||||||||||||||||
Name authority | (Michaux) G. L. Nesom: Phytologia 77: 293. (1995) | (Alexander) G. L. Nesom: Phytologia 77: 294. (1995) | ||||||||||||||||
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