Eurybia sibirica
Eurybia compacta
arctic aster, Siberian aster, Siberian wood-aster
slender aster
1–5+, usually ascending, sometimes decumbent, often purplish, sometimes branched basally, flexuous, proximally sparsely villous, distally usually densely villous, sometimes lanate.
1–8+, erect, simple, strict, glabrescent, usually ± densely villous distally.
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, 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.
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.
slender, villous;
bracts 1–2, often 1 near heads, leaflike (bases sometimes indurate and white as in phyllaries).
campanulate, 6–9 mm, shorter than pappi.
cylindro-campanulate, 6.5–9 mm, slightly shorter than pappi.
12–50;
corollas white to pale violet or purple, 7–17.5 × 0.8–1.8 mm.
(5–)8–14;
corollas blue-violet to rose-purple or bluish, often pale, 5–8(–10) × 1–1.8 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.
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.
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.
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.
1–50, borne singly or in open corymbiform arrays.
3–55+ in flat-topped, corymbiform arrays, branches ascending, slender.
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.
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.
= 18.
= 18.
Eurybia sibirica
Eurybia compacta
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 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.)
BC
WA
Flora NW
PNW Herbaria
WildflowerSearch
iNaturalist
USDA Plants Database
MD Biodiversity
