Eurybia divaricata |
Eurybia compacta |
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aster à rameaux étalés, white wood-aster |
slender aster |
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Habit | Plants 28–90(–120) cm, in ± dense clones (lacking sterile rosettes); rhizomes branched, elongate, becoming woody. | Plants 15–50(–70) cm, in clumps, eglandular; caudices thickened, woody, ovoid to spheric. |
Stems | 1, erect, simple, flexuous, glabrate to sparsely puberulent proximally, densely puberulent distally. |
1–8+, erect, simple, strict, glabrescent, usually ± densely villous distally. |
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, thick, firm (only midnerves conspicuous), margins entire or nearly so, indurate, scabrous, apices indurate, mucronate, faces scabrous (especially distal) to sometimes glabrous, adaxial sometimes villous (especially proximal) at least along midnerves; basal often withering by flowering (bases sometimes marcescent), petioles erect, longer than blades, bases sheathing, winged, ciliate, blades narrowly elliptic to ovate or obovate, 20–70 × 8–20 mm, bases cuneate, margins sometimes crenulate-serrulate, teeth mucronate, apices obtuse to rounded; cauline usually sessile, sometimes subsessile (ascending), lanceolate to oblanceolate, 15–80(–90) × 2.5–12 mm, bases sheathing to auriculate-clasping (distal), apices acute. |
Peduncles | to 1.5 cm, densely hairy, eglandular; bracts 0(–2). |
slender, villous; bracts 1–2, often 1 near heads, leaflike (bases sometimes indurate and white as in phyllaries). |
Involucres | cylindro-campanulate, 4.2–6 mm, much shorter than pappi. |
cylindro-campanulate, 6.5–9 mm, slightly shorter than pappi. |
Ray florets | 5–10(–12); corollas white, 6–12 × 1.5–2.2 mm. |
(5–)8–14; corollas blue-violet to rose-purple or bluish, often pale, 5–8(–10) × 1–1.8 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. |
10–20; corollas pale yellow, 5.5–6.2 mm, not ampliate, tubes longer than narrowly funnelform throats, lobes triangular, 0.65–0.9 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. |
24–35 in 4–5 series, oblong (outer) to lanceolate (inner), unequal, coriaceous (outer) to membranous (inner), bases indurate, rounded (outer), margins hyaline, narrowly scarious, ± erose, ciliate (outer), apices reflexed, green (except innermost), purple-margined, less scarious, rounded or obtuse (outer) to acuminate (inner), mucronate, abaxial faces glabrous or obscurely puberulent, eglandular. |
Heads | 4–50(–100+) in ± flat-topped corymbiform arrays. |
3–55+ in flat-topped, corymbiform arrays, branches ascending, slender. |
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, cylindro-obconic, 1.75–2.6 mm, ribs 9–12 (crowded), faces glabrate to strigillose; pappi of tawny to cinnamon bristles 5.9–6.2 mm, equaling disc corollas. |
2n | = 18. |
= 18. |
Eurybia divaricata |
Eurybia compacta |
|
Phenology | Flowering late summer–fall. | Flowering midsummer–early fall. |
Habitat | Dry to mesic, eastern deciduous and mixed deciduous woods, edges and clearings, roadsides | Dry, sandy places, dry to moist pinelands, oak-thickets, bogs, barrens |
Elevation | 0–1200(–1700) m (0–3900(–5600) ft) | 0–200 m (0–700 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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DE; GA; MD; NC; NJ; SC; VA
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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 compacta may be extirpated from much of its original range (Georgia, Maryland, South Carolina, Virginia) and may now be of conservation concern. It is present on the Atlantic coastal plains and outer Piedmont. A. Cronquist (1980) stated that it approaches E. surculosa on one hand, and E. avita and E. paludosa on the other. This reflects the close affinity between sections Calliastrum and Heleastrum (see above). I have seen no voucher for the Alabama report. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 374. | FNA vol. 20, p. 377. |
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 gracilis, Aster surculosus var. gracilis |
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 259. (1995) | G. L. Nesom: Phytologia 77: 259. (1995) |
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