Eurybia sibirica
Eurybia ×herveyi
arctic aster, Siberian aster, Siberian wood-aster
aster, Hervey's aster
1–5+, usually ascending, sometimes decumbent, often purplish, sometimes branched basally, flexuous, proximally sparsely villous, distally usually densely villous, sometimes lanate.
1–3+, erect, straight, proximally glabrous, distally sometimes sparsely strigose, stipitate-glandular.
cauline (dark green abaxially, paler grayish green adaxially), firm, ± markedly veined, margins coarsely and sometimes irregularly serrate, sometimes (distal) serrulate or entire, villoso-ciliate, teeth mucronate, slightly incurved, apices obtuse to acute, mucronate, abaxial faces glabrescent to scabridulous, sparsely villous along veins, adaxial sparsely to ± densely villous or villoso-strigose;
proximal winged-petiolate to sessile, petiole bases sheathing, blades spatulate, obovate to oblanceolate, or ovate (smaller than mid), 9–50 × 3–22 mm, bases attenuate to tapering and (in sessile) subclasping;
mid short-petiolate to subpetiolate or sessile, blades lanceolate to lance-ovate, oblong to oblanceolate, or obovate to spatulate, 25–95 × 6–35 mm, gradually reduced distally, bases rounded or subauriculate to widely attenuate or cuneate;
distal (arrays) sessile, lanceolate, lance-ovate, or elliptic to oblanceolate, 8–60 × 1–12 mm, rapidly reduced distally.
basal and cauline, firm, margins slightly revolute, crenate-serrate, scabrous, apices acuminate and mucronate, abaxial faces usually glabrescent to ± scabrous, sometimes ± sparsely strigose, gland-dotted or stipitate-glandular, adaxial sparsely puberulent, stipitate-glandular (increasingly so distally);
basal withering by flowering, long-petiolate, petioles slightly winged, bases dilated and sheathing, sparsely ciliate, ± glandular, blades ovate to elliptic-ovate, 70–120 × 40–65 mm, bases rounded to sometimes slightly oblique;
proximal cauline long-petiolate, petioles shorter and gradually more broadly winged distally, blades ovate to elliptic-ovate, 55–100 × 24–65 mm, gradually reduced distally;
distal winged-petiolate to subpetiolate or sessile, blades ovate or elliptic to lanceolate or oblanceolate, 10–64 × 3–18 mm, gradually reduced distally, bases ± clasping, margins becoming entire (arrays).
villous;
bracts 0–3, sometimes immediately subtending heads, lanceolate or spatulate to linear-lanceolate, leaflike or phyllary-like distally (bases indurate, margins purplish), mostly foliaceous, villous.
firm, straight, 0.4–3.5 cm, sparsely strigose, densely stipitate-glandular;
bracts 0–3, oblong-lanceolate, 3–5 mm, acute, densely stipitate-glandular.
campanulate, 6–9 mm, shorter than pappi.
campanulate, (6–)7–11 mm, shorter than pappi.
12–50;
corollas white to pale violet or purple, 7–17.5 × 0.8–1.8 mm.
10–11;
corollas ± purple, 13.1–13.5 × 1.6–2 mm.
25–125;
corollas yellow becoming purplish, 5–8.1 mm, slightly ampliate, tubes longer than funnelform throats, lobes erect, triangular, 0.5–1.1 mm.
25–40;
corollas cream or light yellow, becoming pinkish, 7.6–8.5 mm, slightly ampliate, tubes longer than narrowly funnelform-campanulate throats, lobes erect, lanceolate-acuminate, 0.9–1.4 mm.
30–80 in 3–4(–5) series, sometimes wholly purplish, usually ± oblong-lanceolate to oblanceolate, sometimes linear-lanceolate (innermost), subequal or ± unequal, membranous, bases indurate, ± rounded, dark green zones lanceolate or truncate at base, in distal 1/3–4/5+ (outer, often foliaceous, sometimes bractlike and surpassing involucres) to 1/4–2/3 (inner), margins hyaline, often purplish, narrowly scarious, erose, densely villoso-ciliate, apices squarrose, acute, apiculate, faces villous.
(18–)25–40 in (4–)5–6 series, appressed, lanceolate (outer) or lance-ovate to oblong or linear-oblong (inner; innermost longer than 7 mm), strongly unequal, bases indurate, rounded adaxially, dark-green zones obovate to lanceolate (inner), ca. 1/3 distal portion, margins hyaline or often purplish (inner), scarious, erose, ± ciliate, apices (at least some) reflexed, ± squarrose, or twisted, rounded to obtuse (outer) or acute (inner), abaxial faces stipitate-glandular.
1–50, borne singly or in open corymbiform arrays.
(3–)8–19+ in open, corymbiform arrays.
brown, fusiform, compressed, 2.5–3.7 mm, ribs 7–10 (stramineous), faces strigillose;
pappi of dark cinnamon or reddish tan (sometimes apically clavellate) bristles 5.5–7.5 mm, ± equaling disc corollas.
dark reddish brown, cylindro-fusiform, compressed, ca. 3 mm (sterile or undeveloped), ribs [not seen], faces strigillose;
pappi of tawny, (sometimes apically ± clavate) bristles 7.6–8+ mm, equaling disc corollas.
= 18.
= 72.
Eurybia sibirica
Eurybia ×herveyi
Eurybia sibirica is known from the northern Rocky Mountains and the northern Pacific Coast northward, becoming frequent in Alaska, Yukon, and in the boreal forest region of the continental Northwest Territories; it crosses into Siberia to reach Scandinavia (R. Elven 1989). In British Columbia, northern individuals belong to E. sibirica, not E. pygmaea (contra G. W. Douglas et al. 1998–2002, vol. 1), and southern specimens sometimes are E. merita. G. L. Nesom (1994b) recognized three varieties, two of which have been reported from North America (var. sibirica and var. gigantea). At present, however, given the great phenotypic plasticity of this species, it appears preferable not to recognize varieties, pending studies on the validity of these entities. Eurybia sibirica has often been confused at its southern range limit with E. merita, from which it differs by its often more low-cespitose habit (versus more erect habit, but smaller individuals may be similar in this respect), usually more serrate leaves (versus subserrate to nearly entire), and subequal, foliaceous, purplish phyllaries (versus unequal, non-foliaceous, purple-margined). At the southern end of its range, near the Canada–United States border, E. sibirica is usually found at higher elevations than its congener, there at its northern limit. Aster sibiricus forma albinus Lepage is merely a color variant of the species and is not recognized here.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Eurybia ×herveyi is the F1 hybrid between E. macrophylla and E. spectabilis. L. J. Uttal (1962) proved its origin with artificial crosses, and pointed out that the two parents co-occur in some populations where their ranges overlap.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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