Eurybia integrifolia |
Eurybia sibirica |
|
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thick-stem aster |
arctic aster, Siberian aster, Siberian wood-aster |
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Habit | Plants 15–70 cm, usually in clumps, sometimes in large clones, densely long-stipitate-glandular distally; woody, branched, thick, usually short rhizomes or short caudices. | Plants (1–)5–60 cm; clonal and clumped, eglandular; rhizomes creeping to ascending, scaly, woody with age. |
Stems | 1–3+, straight, stout, glabrous or sparsely hispid proximally, distally ± hispido-villous. |
1–5+, usually ascending, sometimes decumbent, often purplish, sometimes branched basally, flexuous, proximally sparsely villous, distally usually densely villous, sometimes lanate. |
Leaves | basal and cauline, firm, margins entire, strigoso-ciliate, distal also stipitate-glandular, apices mucronate, faces glabrous or glabrescent to ± densely hispid or strigose (then ± scabrous), particularly on veins, midveins sometimes notably hispido-villous, proximally ± sparsely, distally ± densely stipitate-glandular; basal and proximal cauline long-petiolate (to 100+ mm), petioles ± broadly winged, bases sheathing or auriculate-clasping, blades ovate-lanceolate to narrowly elliptic or oblanceolate, 33–180+ × 11–50 mm, bases attenuate, apices acute or obtuse to rounded; mid sessile, blades oblong or oblanceolate to oblong-lanceolate, lanceolate, or lance-ovate, 30–140 × 7–27 mm, gradually reduced distally, bases auriculate-clasping, apices usually acute, rarely obtuse; distal (arrays) narrowly ovate to lanceolate, 9–50 × 3–20 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. |
Peduncles | ± densely long-stipitate-glandular; bracts 0(–2), densely stipitate-glandular. |
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, 8–14 mm, much shorter than pappi. |
campanulate, 6–9 mm, shorter than pappi. |
Ray florets | 8–27; corollas violet-purple, 10–15 × 1.2–2.2 mm. |
12–50; corollas white to pale violet or purple, 7–17.5 × 0.8–1.8 mm. |
Disc florets | 20–50; corollas pale yellow turning pinkish or purplish, 6–7.8 mm, slightly ampliate, tubes much shorter than cylindric to narrowly funnelform throats, lobes erect, lanceolate, 0.6–0.8 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. |
Phyllaries | 25–40 in 3–4 series, inner often purplish, oblong-lanceolate (outer) to linear-lanceolate (inner), ± unequal, membranous, bases pale, indurate, sometimes rounded (outer), distally foliaceous (3/4+ in outer, seldom to base, to 1/5 in inner) and wider than bases, margins narrowly scarious (non-foliaceous parts), purplish (at least inner), ciliate and/or stipitate-glandular (along foliaceous parts), apices squarrose, usually acute, sometimes acuminate, faces densely 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. |
Heads | 3–41+ in elongate, racemo-corymbiform arrays, branches ascending. |
1–50, borne singly or in open corymbiform arrays. |
Cypselae | greenish stramineous, fusiform-obconic, slightly compressed, 4.2–4.7 mm, ribs 7–10, faces ± densely hirtellous; pappi of stramineous to tawny bristles 7–8 mm, ± equaling 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 | = 18. |
= 18. |
Eurybia integrifolia |
Eurybia sibirica |
|
Phenology | Flowering summer–early fall. | Flowering summer. |
Habitat | Drier meadows, open, moist woodlands, in sedge-willow, sagebrush, Douglas fir, and spruce communities | 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 | 1600–3200 m (5200–10500 ft) | 0–2200 m (0–7200 ft) |
Distribution |
CA; ID; MT; NV; OR; UT; WA; WY
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AK; ID; MT; AB; BC; NT; NU; YT; n Eurasia
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Discussion | Eurybia integrifolia is found in mountain ranges bordering the Basin and Range Province, from the Sierra Nevada and Cascade ranges in the west to the Rocky Mountains and Colorado Plateau in the east. (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 | Asteraceae > tribe Astereae > Eurybia | Asteraceae > tribe Astereae > Eurybia |
Sibling taxa | ||
Synonyms | Aster integrifolius, Aster amplexifolius | 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 | (Nuttall) G. L. Nesom: Phytologia 77: 260. (1995) | (Linnaeus) G. L. Nesom: Phytologia 77: 261. (1995) |
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