Erigeron asperugineus |
Erigeron compositus |
|
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Idaho daisy, Idaho fleabane |
cut-leaf daisy, cut-leaf fleabane, dwarf mountain fleabane, fern-leaf fleabane, trifid mountain fleabane, vergerette à feuilles segmentées |
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Habit | Perennials, 2–20 cm; slenderly taprooted, caudices usually branched. | Perennials, 5–15(–25 cm); taprooted, caudices simple or branches usually relatively thick and short, rarely slender and rhizomelike, covered with persistent leaf bases. |
Stems | usually decumbent-ascending, moderately to densely hirsutulous to hirtellous (hairs usually deflexed), eglandular. |
erect (simple, ± scapiform), sparsely hispido-pilose, minutely glandular. |
Leaves | basal (persistent) and cauline; basal blades 1-nerved or weakly 3-nerved, spatulate, rhombic-elliptic to obovate or oblanceolate (often folding), 20–50(–80) × 3–10(–13) mm; cauline gradually or abruptly reduced and linear distally (bases abruptly contracted to petioles), margins entire, faces moderately to densely hirsutulous, eglandular. |
mostly basal (persistent); blades spatulate to obovate-spatulate, 5–50(–70) × (2–)4–12 mm, margins (1–)2–3(–4)-ternately lobed or dissected, cauline bractlike, mostly entire, faces densely hispiduloso-puberulent to glabrate, minutely glandular. |
Involucres | 5–9 × 7–14 mm. |
5–10 × 8–20 mm. |
Ray florets | 10–25; corollas deep blue or violet to rose-purple, 5–10 mm, laminae not coiling or reflexing. |
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Ray (pistillate) florets | 20–60; corollas white to pink or blue, usually 6–12 mm, often reduced to tubes (heads disciform), laminae not coiling or reflexing. |
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Disc corollas | 4.2–6.3 mm. |
3–5 mm. |
Phyllaries | in 3–4 series (tips and margins often purple), sparsely to moderately hirsutulous, densely minutely glandular. |
in 2–3 series (purple-tipped), hirsute (hairs spreading), minutely glandular. |
Heads | 1(–2). |
(sometimes disciform) 1. |
Cypselae | 2.5–3.1 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 20–30 bristles. |
1.6–2.7 mm, 2-nerved, faces sparsely strigose-hirsute; pappi: outer usually of setae, sometimes 0, inner of 12–20 bristles. |
2n | = 18, 36, 45, 54. |
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Erigeron asperugineus |
Erigeron compositus |
|
Phenology | Flowering Jul–Aug. | Flowering (May–)Jun–Aug. |
Habitat | Rocky or gravelly slopes and ridges, talus, sagebrush or meadow edges, limber pine, whitebark pine, fir-pine | Sagebrush, rabbitbrush, aspen to aspen-fir, subalpine meadows, cliffs, talus, and boulders |
Elevation | (2100–)2500–3300 m ((6900–)8200–10800 ft) | (in e Canada, possibly Greenland and Arctic bridge gap, 10–200–)1800–4300 m ((in e Canada, possibly Greenland and Arctic bridge gap, 0–700–)5900–14100 ft) |
Distribution |
ID; MT; NV; UT
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AK; AZ; CA; CO; ID; MT; ND; NV; OR; SD; UT; WA; WY; AB; BC; NF; NT; NU; QC; SK; YT; Greenland; e Asia (Russian Far East)
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Discussion | Erigeron asperugineus sometimes is very similar in aspect to E. clokeyi var. pinzliae; the latter differs in its narrower leaves, coarsely ciliate petioles, broader and non-reflexing rays, and shorter cypselae. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Correlations among ploidal level, breeding systems, and morphologic variation have been studied in detail in Erigeron compositus. Five informally designated population systems of diploids are geographically restricted (all of the northwestern United States and adjacent Canada) and primarily sexual, compared to the polyploids, which are agamospermous and apparently of hybrid origin, at least in some cases (R. D. Noyes et al. 1995; Noyes and D. E. Soltis 1996). Reduction in ray floret laminae usually is correlated with polyploidy. Plants with 1-ternately lobed leaves have been identified as var. glabratus, an element of variation that does not have a geographic pattern. Among closely related species, Erigeron compositus is the only one that produces strongly thickened caudex branches; occasional collections show a tendency toward the slender, loose branches characteristic of the other species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 306. | FNA vol. 20, p. 300. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Aster asperugineus | E. compositus var. discoideus, E. compositus var. glabratus, E. compositus var. multifidus, E. gormanii |
Name authority | (D. C. Eaton) A. Gray: Notes Compositae, 91. (1880) | Pursh: Fl. Amer. Sept. 2: 535. (1813) |
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