Symphyotrichum georgianum |
Symphyotrichum boreale |
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Georgia aster |
aster boréal, northern bog aster, rush American-aster, rush aster, rush or slender white or northern bog aster, slender white aster |
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Habit | Perennials, 50–100 cm, colonial; rhizomatous, woody. | Perennials (5.5–)13–85 cm, colonial; slender (0.6–2.8 mm diam.), long-rhizomatous (rhizomes of season shallow- or deep-seated, not producing rosettes near parent stems). |
Stems | 1–5+, erect, straight (± stout, light to dark brown), proximally sparsely to moderately short-strigose, distally densely so, stipitate-glandular. |
1–3+, erect (straight, slender, often reddish to slightly glaucous proximally), glabrous. |
Leaves | (dark green) thick, firm, margins revolute (sometimes ± undulate), scabrous; basal early deciduous, sessile or subpetiolate, blades spatulate to obovate [size unknown], bases cuneate, margins entire to ± serrate, apices acute, faces finely scabrous; proximal cauline withering by flowering, sessile, blades (adaxially obscurely veined) oblong to lanceolate or narrowly obovate to oblanceolate, proximalmost ± pandurate, 20–70 × 10–20 mm, gradually reduced distally, bases auriculate-clasping, margins entire, finely scabrous, faces finely scabrous, stipitate-glandular; distal sessile, blades lanceolate to oblanceolate, 14–50 × 6–11 mm, reduced distally (much smaller on branches and grading ± abruptly into bracts), bases ± auriculate-clasping to subclasping, margins entire, apices mucronate to white-spinulose, faces scabrous, sometimes sparsely to moderately stipitate-glandular. |
stiff, margins entire to sparsely subserrulate, revolute, scabrellous, apices mucronulate, sometimes with callous point, faces glabrous, abaxial midveins sometimes sparsely strigillose; basal withering by flowering, subpetiolate to petiolate, petioles winged, base dilated, sheathing, eciliate, blades linear-oblanceolate to ovate or suborbiculate, 20–150 × 5–60 mm, bases attenuate, margins shallowly serrate or entire, apices obtuse to rounded; proximal cauline withering by flowering, sessile or subpetiolate, petioles widely winged, bases strongly clasping, blades linear-lanceolate to linear, 15–90 × 2–12 mm, bases attenuate to cuneate or subauriculate, ± clasping, apices obtuse to acute; distal sessile, blades linear-lanceolate (sometimes lanceolate) to linear, (40–)60–150 × 2–6(–8) mm, ± reduced distally, bases subauriculate, subclasping, margins entire or sometimes remotely serrulate, apices acute. |
Peduncles | densely short-strigose, ± densely short-stipitate-glandular, bracts 1–8+, spreading to reflexed, linear to narrowly oblong-lanceolate, strigillose, stipitate-glandular, grading into phyllaries. |
0.5–5 cm, glabrous, bracts 1–3, remote, linear-lanceolate to linear, reduced distally, not grading into phyllaries (sometimes subtending heads). |
Involucres | campanulate to hemispheric, 8–10 mm. |
cylindro-campanulate, (4–)5–8 mm. |
Ray florets | 12–24; corollas lavender violet to dark reddish purple, laminae 14–24 × 1.5–3.5 mm. |
(15–)25–35(–41); corollas white to often pale rose, pale purple or lavender, laminae (7–)10–15(–20) × 1.1–1.5 mm. |
Disc florets | 20–40; corollas white with purplish lobes, 7–9 mm, throats cylindro-funnelform (sparsely pilose), lobes narrowly triangular, 0.7–1.5 mm (sparsely glandular). |
(15–)25–30(–40); corollas cream or pale yellow becoming pink or brown purple, 3.7–6.6 mm, tubes shorter than funnelform throats, lobes triangular, 0.5–1 mm. |
Phyllaries | in 4–7 series, spatulate-oblong to lanceolate, unequal, innermost linear-lanceolate, bases tan, ± indurate in proximal 1/3–1/2, margins hyaline, not (outer) to narrowly scarious, strigoso- or hispido-ciliate, sometimes also stipitate-glandular (foliaceous apices), green zones lanceolate-spatulate, covering distal 1/2 or less, foliaceous apically, apices acute (outer) to acuminate or ± caudate (inner), spreading or reflexed (longer, inner), often purplish, faces moderately strigillose, stipitate-glandular. |
in 4–5 series, usually appressed, rarely outer recurved, lanceolate or oblong-lanceolate (outer) to linear (innermost) ± unequal to sometimes subequal, bases indurate 1/3–1/2 (sometimes not indurate), margins scarious, erose, hyaline or tinged with reddish purple, sparsely ciliolate, green zones lanceolate to linear-lanceolate, apices acute to acuminate, mucronate to apiculate, often purple or reddish purple (particularly inner), faces glabrous. |
Heads | in narrow, racemiform to ± broad, paniculiform arrays, sometimes borne singly on branches, branches initially patent then ascending, leafy. |
borne singly or in open, often lax, racemiform or paniculiform arrays, branches ascending, sparsely leafy. |
Cypselae | gray-brown, narrowly obovoid, compressed, 2.5–4 mm, 7–10-nerved, faces sparsely strigose; pappi tan to tawny, 9–11 mm. |
yellowish tan or purple to brownish with purple streaks or grayish tan (nerves stramineous), obovoid, ± compressed, 0.6–2 mm, 3–5-nerved, faces sparsely strigillose; pappi white, 2.7–6.4 mm. |
2n | = 50. |
= 16, 32, 48, 64. |
Symphyotrichum georgianum |
Symphyotrichum boreale |
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Phenology | Flowering Oct–Nov. | Flowering Aug–Oct. |
Habitat | Sandy and clay soils, oak-pine woodlands, road embankments (mostly Piedmont) | Mostly calcareous areas, fens, marshes, bogs, open cedar-tamarack-spruce swamps, stream and pond margins, wet meadows, swales |
Elevation | 0–300 m (0–1000 ft) | 0–1500+ m (0–4900+ ft) |
Distribution |
AL; FL; GA; NC; SC |
AK; CO; IA; ID; IL; IN; MA; MI; MN; MT; ND; NE; NH; NJ; NY; OH; PA; SD; VT; WA; WI; WV; WY; AB; BC; MB; NB; NF; NS; NT; NU; ON; PE; QC; SK; YT
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Discussion | Of conservation concern. Symphyotrichum georgianum is disjunct and rare in southwestern Georgia and Leon County, Florida. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Some of the western populations originally determined as Symphyotrichum boreale in western Wyoming and adjacent Montana are referable to S. welshii. Those of eastern Wyoming, Colorado, and the Black Hills are S. boreale. There is a gap between the ranges of the two species in Wyoming where neither occurs. Symphyotrichum ×longulum (E. Sheldon) G. L. Nesom (syn. Aster longulus E. Sheldon), reported from Minnesota, is the hybrid between S. boreale and S. puniceum var. puniceum. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 490. | FNA vol. 20, p. 522. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Aster georgianus, Aster patens var. georgianus, Virgulus georgianus, Virgulus patens var. georgianus | Aster laxifolius var. borealis, Aster borealis, Aster franklinianus, Aster junciformis |
Name authority | (Alexander) G. L. Nesom: Phytologia 77: 282. (1995) | (Torrey & A. Gray) Á. Löve & D. Löve: Taxon 31: 358. (1982) |
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