Erigeron nematophyllus |
Erigeron compositus |
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needle-leaf 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, 4–18 cm; taprooted, caudex branches relatively short, thick. | 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 | erect (greenish), usually closely appressed-strigose, sometimes glabrate, eglandular. |
erect (simple, ± scapiform), sparsely hispido-pilose, minutely glandular. |
Leaves | mostly basal or basal (persistent, persistent portion relatively long and slender-fibrous) and cauline (greenish); basal blades 1-nerved linear to linear-oblanceolate or oblanceolate or narrowly spatulate, (20–)30–80 × (0.5–)1–3 mm; cauline reduced distally (bases attenuate, not thickened and whitish-indurate) margins entire (apices obtuse or rounded), faces abaxially glabrous or glabrate, adaxially sparsely strigose, 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 | (3.5–)4-–6.5 × (5–)6–13 mm. |
5–10 × 8–20 mm. |
Ray florets | 15–55; corollas white to pink, 4–8 mm, 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. |
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Disc corollas | (2.8–)3.5–4.3 mm. |
3–5 mm. |
Phyllaries | in 2–4 series (greenish or sometimes purple, margins thickened), strigose to loosely strigoso-hirsute, sometimes more densely so on distal 1/3, sparsely minutely glandular. |
in 2–3 series (purple-tipped), hirsute (hairs spreading), minutely glandular. |
Heads | 1(–3 rarely, from branches at midstem). |
(sometimes disciform) 1. |
Cypselae | 2.2–2.9 mm, 2-nerved, faces and margins villoso-hirsute, sometimes more densely so on nerves; pappi: outer of setae, inner of 15–25 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 nematophyllus |
Erigeron compositus |
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Phenology | Flowering May–Aug. | Flowering (May–)Jun–Aug. |
Habitat | Sagebrush to pinyon-juniper and yellow pine, shale and sandstone, ridges, bases of cliffs, shale gravel, clay flats with Artemisia | Sagebrush, rabbitbrush, aspen to aspen-fir, subalpine meadows, cliffs, talus, and boulders |
Elevation | 1700–2900 m (5600–9500 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 |
CO; UT; WY
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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 | 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.) |
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Source | FNA vol. 20, p. 293. | FNA vol. 20, p. 300. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. compositus var. discoideus, E. compositus var. glabratus, E. compositus var. multifidus, E. gormanii | |
Name authority | Rydberg: Bull. Torrey Bot. Club 32: 124. (1905) | Pursh: Fl. Amer. Sept. 2: 535. (1813) |
Web links |