Eurybia divaricata |
Eurybia spinulosa |
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aster à rameaux étalés, white wood-aster |
Apalachicola aster |
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Habit | Plants 28–90(–120) cm, in ± dense clones (lacking sterile rosettes); rhizomes branched, elongate, becoming woody. | Plants 20–70 cm; solitary or clumped, eglandular; rhizomes short and stout or elongate and wiry, or caudices. |
Stems | 1, erect, simple, flexuous, glabrate to sparsely puberulent proximally, densely puberulent distally. |
1(–3+), erect, simple, ± villous to glabrescent. |
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. |
strongly basal and cauline, linear, firm, ± fleshy, margins indurate, ± revolute, entire to spinose-serrate, smooth to remotely scabridulous or ciliate, spines indurate, finely parallel-veined with evident midribs, apices acute, revolute-indurate, faces glabrescent (minute hairs bulbous at base, threadlike distally); basal and proximal cauline persistent, sessile or petiolate (narrowing between bases and blades), blades lance-linear to linear, 100–300 × (1–)2–5 mm, bases ± marcescent, sheathing, ciliate; cauline sessile, blades linear to lance-linear, 20–95 × 3–5 mm, progressively reduced distally, bases rounded- to auriculate-clasping, adaxial faces sparsely villous in distal, the distal subtending heads boat-shaped. |
Peduncles | to 1.5 cm, densely hairy, eglandular; bracts 0(–2). |
0 (usually) or ascending, 1–17+ mm, sparsely villosulous; bracts 0–2, ascending, lanceolate, bases not indurate, rounded (boat-shaped), margins ciliate, faces glabrous. |
Involucres | cylindro-campanulate, 4.2–6 mm, much shorter than pappi. |
campanulate, 6.5–9.7 mm, shorter than pappi. |
Ray florets | 5–10(–12); corollas white, 6–12 × 1.5–2.2 mm. |
8–17; laminae pale purple to purplish white, 10–16(–20) × 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. |
18–30; corollas yellow, 5.5–7.6 mm, barely ampliate, tubes much shorter than tubular-funnelform throats (1–2 mm), lobes erect, lanceolate, 0.65–1 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. |
20–40 in 4–5 series, green, often ± involute in distal 1/2–2/3 (outer) to 1/3 (inner), densely nerved (nerves not thickened), lanceolate, unequal, coriaceous, bases indurate, rounded (outer), margins entire, indurate (outer) or scarious and often purplish (inner), sparsely ciliate, apices acute to acuminate, indurate, apiculate, adaxial faces glabrous or sparsely villosulous. |
Heads | 4–50(–100+) in ± flat-topped corymbiform arrays. |
3–16+ in spiciform to narrow, racemiform 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. |
brown to gray-brown, fusiform, ± compressed, 2–2.5 mm, ribs 7–10, faces ± strigillose; pappi of burnt-orange (coarse, sometimes apically clavellate) bristles 6–7.5 mm, as long as or slightly longer than disc corollas. |
2n | = 18. |
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Eurybia divaricata |
Eurybia spinulosa |
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Phenology | Flowering late summer–fall. | Flowering May–Jul. |
Habitat | Dry to mesic, eastern deciduous and mixed deciduous woods, edges and clearings, roadsides | Moist to dry, acid sandy peats, savannas in long-leaf pinelands, fire-maintained |
Elevation | 0–1200(–1700) m (0–3900(–5600) ft) | 0–50 m (0–200 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 |
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.) |
Of conservation concern. Eurybia spinulosa is known only from the Apalachicola River drainage of the Florida panhandle; it is of conservation concern in Florida and is a facultative wetland indicator. Much of its habitat has now been lost to development (R. Kral 1983, vol. 2). Kral published a map of the species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 374. | FNA vol. 20, p. 381. |
Parent taxa | ||
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 spinulosus, Heleastrum spinulosum |
Name authority | (Linnaeus) G. L. Nesom: Phytologia 77: 259. (1995) | (Chapman) G. L. Nesom: Phytologia 77: 262. (1995) |
Web links |