Eurybia divaricata |
Eurybia radulina |
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aster à rameaux étalés, white wood-aster |
rough-leaf aster, rough-leaf wood-aster |
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Habit | Plants 28–90(–120) cm, in ± dense clones (lacking sterile rosettes); rhizomes branched, elongate, becoming woody. | Plants 10–70 cm, laxly cespitose (grayish green), eglandular; rhizomes elongate, slender, woody. |
Stems | 1, erect, simple, flexuous, glabrate to sparsely puberulent proximally, densely puberulent distally. |
1–3, ascending to erect, often purple, simple, flexuous, proximally glabrescent or sparsely villous, distally ± densely villous. |
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. |
cauline, firm, margins slightly revolute, coarsely serrate or (distal) entire, scabrous to strigoso-ciliate, teeth mucronate, ± markedly veined, apices mucronate, abaxial faces scabrous, adaxial scabroso-strigose; proximal mostly withering by flowering, petioles winged, shorter than blades, bases clasping, blades elliptic to obovate 12–45+ × 7–20+ mm, smaller than mid, apices obtuse; mid narrowly winged-petiolate (petioles short with ± clasping bases), distally subpetiolate or sessile, blades ovate or elliptic to broadly oblanceolate or obovate, 32–85(–130) × 4–40 mm, gradually reduced distally, bases usually attenuate, sometimes cuneate, apices obtuse to acute; distal (arrays) oblanceolate to lanceolate, 5–28 × 1–8 mm, more sharply reduced. |
Peduncles | to 1.5 cm, densely hairy, eglandular; bracts 0(–2). |
densely villous; bracts 0–1, scabroso-strigose. |
Involucres | cylindro-campanulate, 4.2–6 mm, much shorter than pappi. |
campanulate, 6–9 mm, shorter than pappi. |
Ray florets | 5–10(–12); corollas white, 6–12 × 1.5–2.2 mm. |
10–15; corollas white to sometimes pale violet or purple, 8.5–11(–13) × 1.3–2.3 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. |
30–70; corollas yellow becoming purple- or pinkish-tinged, 6–7(–8) mm, ± ampliate, tubes equaling to longer than funnelform-campanulate throats, lobes usually erect, sometimes ± spreading, lanceolate, 1–1.3 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. |
38–62 in 4–5 series, midnerves slightly raised (outer), oblong (outer) to lanceolate-linear or linear (inner), unequal, membranous, bases indurate, ± rounded, green zones to scarious margins in distal 1/3–1/2 (outer; seldom ± wholly foliaceous) to 1/5 or none (inner), margins often purple, hyaline, narrowly scarious, erose, densely villoso-ciliate, apices appressed, sometimes purplish-tinged, usually acute, sometimes obtuse, adaxial faces villous. |
Heads | 4–50(–100+) in ± flat-topped corymbiform arrays. |
5–30+ in flat-topped, corymbiform arrays. |
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. |
tawny, fusiform, 3–3.5 mm, slightly compressed, ribs 7–9 (brown, translucent), faces strigillose; pappi of tawny bristles 2.7–3 mm, ± equaling disc corollas. |
2n | = 18. |
= 18, 27. |
Eurybia divaricata |
Eurybia radulina |
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Phenology | Flowering late summer–fall. | Flowering summer. |
Habitat | Dry to mesic, eastern deciduous and mixed deciduous woods, edges and clearings, roadsides | Dry rock outcrops, edges of forests, open forests, mostly on slopes, foothill oak woodlands, oak, oak-fir, yellow pine forests |
Elevation | 0–1200(–1700) m (0–3900(–5600) ft) | (10–)100–1600 m ((0–)300–5200 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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CA; OR; WA; BC
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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 radulina is confined mostly west of the Cascades, from southern Vancouver Island (British Columbia) to the southern Coast Ranges, north Channel Islands, and central Sierra Nevada in California. It often is confused with E. merita in the western, coastal states where both are found, though populations are rarely if ever sympatric, the former apparently thriving at lower elevations than the latter. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 374. | FNA vol. 20, p. 369. |
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 radulinus, Aster eliasii, Weberaster radulinus |
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 259. (1995) | (A. Gray) G. L. Nesom: Phytologia 77: 261. (1995) |
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