Erigeron cervinus |
Erigeron compositus |
|
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Siskiyou daisy, Siskiyou 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, (10–)15–30 cm; rhizomatous, fibrous-rooted, caudices or rhizomes sometimes with relatively short or elongate, slightly woody branches. | 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 | ascending-erect, glabrous, sometimes minutely glandular distally. |
erect (simple, ± scapiform), sparsely hispido-pilose, minutely glandular. |
Leaves | basal (often persistent) and cauline; basal blades spatulate to obovate or oblanceolate, (10–)40–80(–120) × 4–12(–15) mm; cauline equal-sized or gradually reduced distally (bases sometimes weakly subclasping), margins entire, faces glabrous, 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 | 5–7 × 9–14 mm. |
5–10 × 8–20 mm. |
Ray florets | 20–45; corollas blue to purplish, 7–10 mm (mostly 1.5–3 mm wide), laminae coiling. |
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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. |
|
Disc corollas | 3.5–4.9 mm. |
3–5 mm. |
Phyllaries | in 2–3(–4) series, glabrous, densely minutely glandular. |
in 2–3 series (purple-tipped), hirsute (hairs spreading), minutely glandular. |
Heads | 1(–4). |
(sometimes disciform) 1. |
Cypselae | 1.5–1.7 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 12–15 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. |
|
Erigeron cervinus |
Erigeron compositus |
|
Phenology | Flowering (May–)Jun–Aug(–Sep). | Flowering (May–)Jun–Aug. |
Habitat | Open, rocky slopes and streamsides, seeps, crevices in walls, meadows, pine to fir woods, chaparral, sometimes over serpentine | Sagebrush, rabbitbrush, aspen to aspen-fir, subalpine meadows, cliffs, talus, and boulders |
Elevation | (50–)900–2300 m ((200–)3000–7500 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 |
CA; OR
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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 | Plants with relatively elongate basal leaves and cauline leaves little reduced distally (identified as Erigeron delicatus) are much different in general aspect; intermediates bridge the morphologic extremes. (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. 335. | FNA vol. 20, p. 300. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. delicatus | E. compositus var. discoideus, E. compositus var. glabratus, E. compositus var. multifidus, E. gormanii |
Name authority | Greene: Pittonia 3: 163. (1897) | Pursh: Fl. Amer. Sept. 2: 535. (1813) |
Web links |