Eurybia schreberi
Eurybia sibirica
Schreber's aster, Schreber's wood-aster
arctic aster, Siberian aster, Siberian wood-aster
1, erect, simple, straight, proximally glabrous or sparsely villous, distally densely villous.
1–5+, usually ascending, sometimes decumbent, often purplish, sometimes branched basally, flexuous, proximally sparsely villous, distally usually densely villous, sometimes lanate.
basal and cauline, margins coarsely serrate (proximal) to serrate (distal), strigoso-ciliate, teeth (15–30 per side) mucronulate, apices acuminate, abaxial faces sparsely strigose, long-stipitate-glandular on veins, adaxial sparsely villous, more densely so on veins;
basal withering by flowering, petiolate (55–180 mm), bases sheathing, blades broadly ovate, 55–110 × 48–95 mm, bases cordate (with mostly deep, rectangular sinuses);
cauline petiolate to (distal) subsessile, petioles (4–100 mm) ± winged, ± clasping, blades ovate to broadly lanceolate, 27–135 × 7–112 mm, bases cordate (sinuses narrower) to rounded or cuneate-rounded;
distal (arrays) sessile, ovate to lanceolate, 6–70 × 1–27 mm.
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.
sparsely to moderately villous, sparsely glandular;
bracts 0–1, linear.
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.
cylindro-campanulate, 5.5–7.5 mm, equal to or shorter than pappi.
campanulate, 6–9 mm, shorter than pappi.
6–12;
corollas white, 10.5–13 × 1.5–2.1 mm.
12–50;
corollas white to pale violet or purple, 7–17.5 × 0.8–1.8 mm.
12–20(–30);
corollas yellow, 5–6.8 mm, slightly ampliate, tubes (3.2–3.8 mm) longer than campanulate throats (1.1–1.9 mm), lobes erect to slightly spreading, lanceolate, (0.9–)1.1–1.5(–1.9) 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.
23–32 in 4–5 series, oblong (outer) to lanceolate (inner), strongly unequal, bases indurate, dark green zones in distal 1/4 or less (outer), often confined to narrow strip along midnerves or none (inner), margins narrowly scarious, densely villoso-ciliate, apices ± loose, obtuse to rounded, faces glabrous or sparsely villosulous, sometimes sparsely stipitate-glandular.
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.
15–100+ in flat-topped, corymbiform arrays.
1–50, borne singly or in open corymbiform arrays.
brown, fusiform to cylindro-obconic, compressed, 3.2–3.7 mm, ribs 6–12, faces glabrous or sparsely strigillose;
pappi of (65–70) orangish to burnt orange (fine, barbellulate, sometimes apically clavellate) bristles 5–6.8 mm, ± equaling disc corolla.
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.
= 54.
= 18.
Eurybia schreberi
Eurybia sibirica
Eurybia schreberi is rare or extirpated in a many states at the northern limit of its range.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
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