Eurybia conspicua |
Eurybia sibirica |
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showy aster, showy wood-aster, western showy aster |
arctic aster, Siberian aster, Siberian wood-aster |
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Habit | Plants 30–100 cm; forming loose clones, short-stipitate-glandular; rhizomes long to short, woody. | Plants (1–)5–60 cm; clonal and clumped, eglandular; rhizomes creeping to ascending, scaly, woody with age. |
Stems | 1, erect, seldom branched proximally, stout, proximally glabrate to villous and sparsely glandular (sometimes to base), distally glabrate, strongly glandular. |
1–5+, usually ascending, sometimes decumbent, often purplish, sometimes branched basally, flexuous, proximally sparsely villous, distally usually densely villous, sometimes lanate. |
Leaves | cauline, thick, ample, bases clasping, margins ± revolute, sharply serrate (rarely subentire) with ± mucronate teeth, veins prominent, apices acute to acuminate, mucronate, faces scabrous, adaxial veins villous; proximal cauline deciduous by flowering, winged-subpetiolate to sessile, blades oblanceolate to ovate or obovate, smaller than mid, bases tapering; mid usually sessile, sometimes subsessile, obovate or elliptic, (40–)58–140(–180) × (8–)20–50(–80) mm, bases cuneate to mostly rounded-subauriculate; distal (in arrays) sessile, ovate to oblanceolate, lanceolate, or elliptic, (8–)10–60(–90) × 2–28(–40) mm, strongly reduced 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. |
Peduncles | sometimes sparsely hairy, stipitate-glandular; bracts usually 0, sometimes 1–3. |
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. |
Involucres | campanulate, 9–12 mm, shorter than pappi. |
campanulate, 6–9 mm, shorter than pappi. |
Ray florets | 12–35; corollas blue or violet, (8–)10–15 × 1.2–2 mm. |
12–50; corollas white to pale violet or purple, 7–17.5 × 0.8–1.8 mm. |
Disc florets | 48–55; corollas yellow, 9–10 mm, slightly ampliate, tubes narrowly cylindric, slightly longer than narrowly funnelform throats, lobes erect, lanceolate, 0.7–1.3 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. |
Phyllaries | 34–55 in 4–5 series, midnerves translucent, strongly unequal, membranous, bases indurate, dark green distally, margins densely ciliate, apices spreading or ± squarrose, purple (mucro), acute or acuminate (sometimes mucronate), faces glabrous, densely stipitate-glandular; outer ovate or lanceolate; inner oblong-lanceolate, margins hyaline, often purplish distally, scarious. |
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. |
Heads | 5–50 in open corymbiform arrays. |
1–50, borne singly or in open corymbiform arrays. |
Cypselae | tan, fusiform, ± compressed, 3–4 mm, ribs 8–10, appressed-setose; pappi of cinnamon to pinkish bristles 9–10 mm, about as long as disc corollas. |
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. |
2n | = ca. 108, ca. 122. |
= 18. |
Eurybia conspicua |
Eurybia sibirica |
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Phenology | Flowering summer–fall. | Flowering summer. |
Habitat | Open, mesic conifer (spruce-fir, pine, or aspen-conifer) or aspen woods, from foothills to upper montane zone, mesic to dry meadows, forest openings, in somewhat clayey soils, adapted to spring fires | Disturbed, open, gravelly or sandy areas in boreal forest, wet meadows, open aspen and spruce woods, riparian thickets, sandy or gravelly stream flats, stream banks, lakeshores, bluffs, sand dunes, sandy places, subalpine and mountain meadows |
Elevation | 300–2500 m (1000–8200 ft) | 0–2200 m (0–7200 ft) |
Distribution |
ID; MT; OR; SD; WA; WY; AB; BC; MB; SK
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AK; ID; MT; AB; BC; NT; NU; YT; n Eurasia
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Discussion | Eurybia conspicua is a western boreo-montane taxon; it ranges from the Interior Mountains and Plateaus to the Rocky Mountains, and spreads onto the northern Great Plains in the aspen parklands-southern boreal forests of Canada, barely into western Manitoba. It is disjunct to the Black Hills (South Dakota) and Cypress Hills (Alberta-Saskatchewan). It stops at the Canadian Shield due to soil preferences (A. J. Breitung 1988). This taxon has the highest chromosome number in the genus. (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.) |
Source | FNA vol. 20, p. 368. | FNA vol. 20, p. 370. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Aster conspicuus | Aster sibiricus, Aster beringensis, Aster giganteus, Aster montanus, Aster montanus var. giganteus, Aster richardsonii, Aster richardsonii var. giganteus, Aster sibiricus subsp. richardsonii, Aster sibiricus var. giganteus, E. sibirica var. gigantea |
Name authority | (Lindley) G. L. Nesom: Phytologia 77: 259. (1995) | (Linnaeus) G. L. Nesom: Phytologia 77: 261. (1995) |
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