Erigeron oreophilus |
Erigeron compositus |
|
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chaparral fleabane |
cut-leaf daisy, cut-leaf fleabane, dwarf mountain fleabane, fern-leaf fleabane, trifid mountain fleabane, vergerette à feuilles segmentées |
|
Habit | Perennials, (8–)25–90 cm; taprooted, caudices woody. | 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, sparsely hirsuto-villous (hairs 0.6–2 mm) or glabrous, densely stipitate-glandular (at least on distal 1/2, glands relatively large, capitate). |
erect (simple, ± scapiform), sparsely hispido-pilose, minutely glandular. |
Leaves | basal (sometimes withering by flowering) and cauline; basal blades 15–60 × 8–37 mm; cauline gradually reduced distally, margins deeply pinnatifid, lobes 2–4(–5) pairs, faces usually glabrous, stipitate-glandular. |
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 | 4.5–5.5 × 8–12 mm. |
5–10 × 8–20 mm. |
Ray florets | 75–130; corollas white, 8–14 mm, laminae reflexing. |
|
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 | 2.8–3.5 mm. |
3–5 mm. |
Phyllaries | in 3–4 series, glabrous or sparsely hirsute, densely stipitate-glandular. |
in 2–3 series (purple-tipped), hirsute (hairs spreading), minutely glandular. |
Heads | (1–)5–25(–50) in loosely corymbiform arrays. |
(sometimes disciform) 1. |
Cypselae | 1–1.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner (readily falling) of (8–)10–12 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. |
= 18, 36, 45, 54. |
Erigeron oreophilus |
Erigeron compositus |
|
Phenology | Flowering Jul–Oct(–Nov). | Flowering (May–)Jun–Aug. |
Habitat | Open, rocky habitats, cliff ledges or crevices, grassland, chaparral, oak, pine, pine-fir | Sagebrush, rabbitbrush, aspen to aspen-fir, subalpine meadows, cliffs, talus, and boulders |
Elevation | 1100–2800(–3100) m (3600–9200(–10200) 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 |
AZ; NM; Mexico (Chihuahua, Durango, Sonora)
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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 oreophilus is similar to E. neomexicanus in its perennial habit, typically pinnatifid leaves, white, reflexing rays, and 10–12 readily falling pappus bristles; it has a vestiture of dense, viscid, stipitate glands and sparse, spreading, nonglandular hairs. (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. 278. | FNA vol. 20, p. 300. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Achaetogeron pringlei, E. delphiniifolius var. oreophilus | E. compositus var. discoideus, E. compositus var. glabratus, E. compositus var. multifidus, E. gormanii |
Name authority | Greenman: Proc. Amer. Acad. Arts 41: 257. (1905) | Pursh: Fl. Amer. Sept. 2: 535. (1813) |
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