Eurybia divaricata |
Eurybia paludosa |
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aster à rameaux étalés, white wood-aster |
southern swamp aster |
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Habit | Plants 28–90(–120) cm, in ± dense clones (lacking sterile rosettes); rhizomes branched, elongate, becoming woody. | Plants 20–80 cm; in clumps and clones, eglandular; rhizomes creeping, herbaceous and thin, becoming thick and woody, scaly. |
Stems | 1, erect, simple, flexuous, glabrate to sparsely puberulent proximally, densely puberulent distally. |
1–10+, erect, often reddish, simple, straight (brittle), proximally glabrous, glabrescent, or sparsely strigillose, distally strigillose or ± villoso-hirsute (at least in arrays). |
Leaves | basal and cauline, thin, margins sharply serrate, teeth (6–15 per side) mucronulate, ciliate, apices acuminate, abaxial faces sparsely strigose or villous, particularly villous along veins, adaxial glabrescent to sparsely strigose, veins sparsely stipitate-glandular; basal and proximal withering by flowering, petiolate (petioles 20–70 mm), blades ovate, 19–65 × 17–60 mm, basal smaller than proximal, bases cordate (sinuses narrow, curved); cauline petiolate, petioles often ± winged (15–70 mm), blades ovate, 20–200 × 10–100 mm, bases cordate to rounded; distal (arrays) usually sessile, sometimes subpetiolate, blades ovate to lanceolate, 5–20 × 1–8 mm, bases rounded. |
basal and cauline, firm, only midnerves evident, margins indurate, entire or sometimes remotely spinulose-serrate, scabrous, spines indurate, ± pronounced, apices mucronate or indurate, abaxial faces glabrous or scabrous, adaxial sparsely hirtellous, distal often more hairy; basal and proximalmost cauline withering by flowering, petioles (often marcescent, to 20 mm), bases sheathing, blades elliptic to lanceolate (basal) or linear-lanceolate, ± arcuate (proximal), 15–103 × 5–9 mm, bases cuneate, apices obtuse (basal) to acute; cauline progressively sessile (petioles more winged) and reduced, blades lanceolate or linear-lanceolate to linear, ± arcuate, 18–132+ × 2–6 mm, margins sometimes revolute, apices acute. |
Peduncles | to 1.5 cm, densely hairy, eglandular; bracts 0(–2). |
ascending, usually mostly 1–10+ cm (seldom not elongating, sometimes those of young heads appearing short or absent), thin, hirtello-puberulent to villoso-hirsute; bracts 2–5, often 1–2 subtending heads, sometimes phyllary-like (bases pale, indurate). |
Involucres | cylindro-campanulate, 4.2–6 mm, much shorter than pappi. |
campanulate, 9–11 mm, much shorter than pappi. |
Ray florets | 5–10(–12); corollas white, 6–12 × 1.5–2.2 mm. |
15–35; corollas deep lavender to purple, (10–)15–20 × 1–2.3 mm. |
Disc florets | 12–19(–25); corollas yellow, 4.1–4.8(–5.5) mm, abruptly ampliate, tubes (2.3–2.6 mm) longer than campanulate throats (0.9–1.2 mm), lobes reflexed, lanceolate, 0.7–1.4 mm. |
25–60; corollas yellow, 5.5–7 mm, slightly ampliate, tubes much shorter than cylindro-funnelform throats, lobes spreading, lanceolate-acuminate, 0.75–1.1 mm. |
Phyllaries | 25–30 in 4–5 series, inner purplish distally, oblong (outer) to lanceolate or linear-lanceolate (inner), strongly unequal, bases indurate, green zones in distal 1/2 (outer) to 1/3 or along distal midveins (inner), margins narrowly scarious, densely fimbriate-ciliate, apices rounded to acute, faces sparsely hairy, sometimes sparsely stipitate-glandular; outer 0.7–1.5 mm wide, lengths seldom more than 2.5 times widths. |
40–65+ in 4–5 series, lanceolate or oblong (outer) to linear-oblanceolate or linear (inner), unequal, membranous, bases indurate, rounded (particularly outer), green zones well defined, slightly expanded in distal 1/3–2/3 (foliaceous), reaching margins (outer wholly foliaceous, outermost are bracts subtending heads) to 1/6 or less and not reaching margins or none (inner), margins sometimes distally purplish (particularly inner), indurate, narrowly scarious, erose proximally to nearly completely so (inner), densely ciliate proximally (scarious part) to distally scabrous (foliaceous part), apices loose and often spreading, sometimes squarrose, obtuse to sometimes acute, mucronate, faces sparsely to densely strigillose. |
Heads | 4–50(–100+) in ± flat-topped corymbiform arrays. |
(1–)4–10+ in open, corymbiform arrays, seldom borne singly, with ascending branches. |
Cypselae | brown, cylindro-obovoid, slightly compressed, 2.6–3.8 mm, ribs 7–10 (tan to stramineous), faces sparsely strigillose; pappi of reddish to cream-colored (fine, barbellulate, sometimes apically ± clavate) bristles 3.7–5 mm, equaling or longer than disc corollas. |
stramineous to tawny, cylindric to narrowly obovoid, slightly compressed, 2.3–3.6 mm, ribs 10–16, sparsely strigillose; pappi of stramineous (firm, sometimes apically clavellate) bristles 5–6.7 mm, ± equaling disc corollas. |
2n | = 18. |
= 36. |
Eurybia divaricata |
Eurybia paludosa |
|
Phenology | Flowering late summer–fall. | Flowering late summer–fall. |
Habitat | Dry to mesic, eastern deciduous and mixed deciduous woods, edges and clearings, roadsides | Moist savannas, margins of pools and swamps, low pinelands, seldom on sand hills of coastal plains, open hammocks |
Elevation | 0–1200(–1700) m (0–3900(–5600) ft) | 0–100 m (0–300 ft) |
Distribution |
AL; CT; DC; DE; GA; KY; MA; MD; ME; MI; NC; NH; NJ; NY; OH; PA; RI; SC; TN; VA; VT; WV; ON; QC [Introduced in Europe (Netherlands)]
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FL; GA; NC; SC
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Discussion | Eurybia divaricata is a mainly Appalachian element of the eastern North American deciduous forest. It is often confused with Eurybia chlorolepis (see W. F. Lamboy 1992 for distinction between the two species), E. schreberi, or Symphyotrichum cordifolium. Lamboy provided a map of the species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Eurybia paludosa is often confused with E. hemispherica, with which it is closely related. It is present on the Atlantic coastal plain from North Carolina to northeastern Florida. The two species are disjunct geographically and ecologically, even when they occur in the same states. In North Carolina, for instance, E. paludosa is coastal while E. hemispherica is found in the mountains. In northern Florida, the former is found only in Nassau County, while the latter is present only in the western panhandle. Their ranges do not overlap. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 374. | FNA vol. 20, p. 380. |
Parent taxa | Asteraceae > tribe Astereae > Eurybia | Asteraceae > tribe Astereae > Eurybia |
Sibling taxa | ||
Synonyms | Aster divaricatus, Aster boykinii, Aster castaneus, Aster corymbosus, Aster corymbosus var. alatus, Aster excavatus, Aster flexilis, Aster stilettiformis, Aster tenebrosus, Biotia corymbosa, Biotia corymbosa var. alata, Biotia macrophylla var. divaricata, E. corymbosa | Aster paludosus, Heleastrum paludosum |
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 259. (1995) | (Aiton) G. L. Nesom: Phytologia 77: 261. (1995) |
Web links |