Eurybia surculosa
Eurybia radula
creeping aster
aster rude, low rough aster, rough wood-aster
1–3+, erect, simple, straight, proximally sparsely strigillose to glabrescent, distally strigose or villoso- or hirsuto-strigose.
1, erect, straight, often reddish, simple, glabrous or glabrescent to sparsely villous proximally, villous distally.
basal and cauline, firm (only midnerves conspicuous), margins slightly revolute, slightly indurate, entire or sometimes remotely crenulate-serrulate, scabrous, teeth indurate, apices acute to obtuse, indurate, often mucronate, abaxial faces scabrous, adaxial sparsely strigose or glabrous;
basal and proximal cauline usually persistent, sometimes withering by flowering (bases often marcescent), petioles sometimes narrowly winged, bases sheathing, blades narrowly elliptic, narrowly ovate, or lanceolate to spatulate, narrowly obovate, or oblanceolate, 13–135 × (2–)6–35 mm (earliest smaller), bases attenuate to cuneate;
mid short-winged-petiolate or sessile, blades lance-oblong, lance-elliptic, lanceolate, or oblanceolate, 22–105 × 3–14 mm, gradually reduced distally, bases slightly auriculate-clasping to cuneate or attenuate;
distal (arrays) sessile, blades lanceolate to linear, 7–42 × 1–6 mm, abruptly reduced.
cauline, rugose-veined, margins ± revolute, ± remotely, ± deeply serrate, scabrous, teeth ± indurate (mucronate), apices mucronulate, abaxial faces scabrous, adaxial ± villous, particularly on veins (increasingly so distally);
proximalmost withering by flowering, winged-petiolate, petioles equaling or longer than blades, bases ± sheathing, sometimes marcescent, blades spatulate to oblanceolate, 10–42 × 3–8 mm, sometimes reduced, smaller than mid, bases attenuate to cuneate, apices obtuse to acute;
mid sessile, lanceolate, oblanceolate, or narrowly obovate to narrowly elliptic or elliptic, (23–)30–115 × 5–36 mm, gradually reduced distally, bases tapering or rounded to ± auriculate-clasping (often narrowed above base), apices acute to acuminate;
distal (arrays) sessile, (6–)10–40 × 2–7 mm.
densely strigose or strigoso-hispid, sometimes sparsely long-stipitate-glandular distally;
bracts (0–)1–3(–6), leaflike to phyllary-like (bases indurate), scabrous or sparsely strigose.
± densely villous;
bracts 0–2, sometimes subtending heads.
cylindro-campanulate, 7–11(–13) mm, shorter than pappi.
campanulate, 5.5–9 mm, shorter than pappi.
13–30;
corollas bluish violet, (8–)11.5–15.5 × 1.5–2.3 mm.
13–30;
corollas pale blue-violet, 10.5–15 × 1.4–2 mm.
25–40;
corollas pale yellow turning purplish, 5–7.2 mm, slightly ampliate, tubes shorter than funnelform throats, lobes erect, deltate to triangular, 0.75–1.1 mm.
37–72;
corollas yellow, 4.5–6 mm, slightly ampliate, 4.8–5.8 mm, tube lengths about twice funnelform throats (2.7–3.4 mm), lobes erect, lanceolate, 0.6–1 mm.
35–65 in 4–5 series, oblong (outer) to linear-oblong or seldom linear (inner), strongly unequal, membranous, bases indurate, rounded (outer), dark green zones foliaceous, sometimes slightly dilated, in distal 1/3–1/2 (outer) to 1/8–1/7 or none and not reaching margins (inner), margins hyaline or sometimes purplish, narrowly scarious, erose, ciliate (scarious parts), ± scabrous (foliaceous parts), sometimes short-stipitate-glandular (innermost), apices spreading to squarrose, obtuse, often dilated (innermost), mucronulate (outer) or apiculate (inner), abaxial faces glabrous or strigillose, both scabrellous on foliaceous parts.
30–50 in 4–5 series, oblong or oblong-lanceolate, seldom ovate (outer), lanceolate to linear-lanceolate (inner), strongly unequal, membranous, bases indurate, rounded (outer), green zones full-width, occasionally purplish (inner), in distal 1/2 (outer; rarely 2/3 and foliaceous) to less than 1/6 and paler or none (inner), margins hyaline (seldom purplish), narrowly scarious, ± erose, densely ciliate, apices usually appressed, often squarrose, usually acute, sometimes obtuse, mucronulate, faces glabrous or sparsely strigillose.
(1–)3–50(–122+), usually in open or dense, corymbiform arrays, seldom borne singly.
1–25+ in open corymbiform arrays or borne singly.
brown, cylindro-obconic, slightly compressed, 3.2–3.5 mm, ribs 8–10, stramineous, strigillose;
pappi of tawny-yellowish to pinkish bristles 5.2–7.1 mm, ± equaling disc corollas.
tawny to stramineous, fusiform to cylindro-obconic, slightly compressed, 2.7–3.5 mm, ribs 8–18 (stramineous or reddish brown), ± crowded, faces glabrous;
pappi of pale cinnamon bristles 4.5–5.2 mm, shorter than disc corollas.
= 36.
= 18.
Eurybia surculosa
Eurybia radula
Eurybia surculosa is of conservation concern in Virginia and Alabama. It is often confused with E. compacta, its close relative from the coastal plains. In states where both are present, it is found only inland in the southern Appalachian Mountains and not on the coastal plains; its larger heads help to differentiate it from E. compacta.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Eurybia radula reaches its northwestern limit south of James Bay in northeastern Ontario, where it is rare (J. C. Semple et al. 2002). It is vulnerable in most of its United States range. Aster radula var. strictus (Pursh) A. Gray (for which no combination exists in Eurybia) appears to be a reduced, more slender plant with 1–8 heads (M. L. Fernald 1950) from more northern parts of the range (Newfoundland and Labrador, northern Quebec, northern Nova Scotia), presumably due to harsher conditions; an entire spectrum of intermediates appears to exist with the typical variety to the south, however, and it is unclear whether the variety should be recognized. It seems that the common name, rough aster, stems from a misinterpretation of the Latin epithet radula, which means scraper (rough would be radulans).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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