Erigeron filifolius |
Erigeron speciosus |
|
---|---|---|
Peck's threadleaf fleabane, thread-leaf daisy, thread-leaf fleabane |
aspen fleabane, showy daisy, showy fleabane, splendid fleabane |
|
Habit | Perennials, 10–30(–50) cm; taprooted, caudices multicipital, often with relatively short and thin, stemlike, lignescent branches. | Perennials, 30–80(–100) cm; rhizomatous, fibrous-rooted, caudices relatively thick. |
Stems | erect, sparsely to densely strigose (hairs loosely appressed to ascending, fine), densely white-strigose at least proximally, eglandular. |
erect, glabrous or sparsely hirsuto-pilose (hairs 0.5–1 mm), often minutely glandular distally. |
Leaves | basal (usually persistent, not clustered as rosettes) and cauline; basal blades linear to filiform, 10–80 × 0.5–2.5(–3.5) mm; cauline gradually or little reduced distally, margins entire, faces sparsely to moderately strigose, eglandular. |
basal (usually withering by flowering) and cauline; basal blades oblanceolate-spatulate, 30–80(–150) × 4–18(–28) mm, margins entire, often ciliate (main veins sometimes also), faces glabrous, eglandular or distal sparsely minutely glandular; cauline blades ovate to ovate-lanceolate, oblong-lanceolate, or lanceolate, nearly even-sized distally or sometimes mid largest (continuing to immediately below heads, bases usually clasping to subclasping). |
Involucres | 4–7 × 5–-18 mm. |
6–9 × 11–22 mm. |
Ray florets | (15–)20–125; corollas usually blue, sometimes white, pink, or pale lavender, 3–13 mm, laminae coiling. |
75–150; corollas blue to lavender, rarely whitish, 8–16 mm (mostly 1 mm wide), laminae slightly coiling at least at tips. |
Disc corollas | 2.5–5.5 mm. |
4–5 mm. |
Phyllaries | in (2–)3–4 series, loosely strigose to hirsute or nearly villous, densely to sparsely minutely glandular. |
in 2–3(–4) series, usually glabrous, sometimes sparsely hirsuto-pilose, minutely glandular. |
Heads | 1–5(–10+) from distal branches, tending to be in corymbiform arrays. |
(2–)4–20 in corymbiform arrays. |
Cypselae | 1.4–1.8(–2) mm, 2-nerved, faces sparsely strigose to glabrate; pappi: outer of setae, inner of 20–30 bristles. |
1.5–1.8 mm, 2(–4)-nerved, faces sparsely strigose; pappi: outer of setae, inner of 20–30 bristles. |
2n | = 18. |
|
Erigeron filifolius |
Erigeron speciosus |
|
Phenology | Flowering May–Aug. | Flowering Jul–Oct. |
Habitat | Dry, rocky or sandy soil, lava beds, bitterbrush, sagebrush, juniper, ponderosa pine | Dry or moist, gravelly or loamy soil, prairies, yellow pine, pine-fir, spruce-fir, aspen-spruce |
Elevation | 400–2400 m (1300–7900 ft) | (600–)900–3400 m ((2000–)3000–11200 ft) |
Distribution |
CA; ID; MT; NV; OR; UT; WA; BC
|
AZ; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; Mexico (Baja California)
|
Discussion | The densely white-strigose stem bases, linear-filiform leaves relatively unreduced distally, and relatively few heads with coiling, usually blue rays are distinctive for Erigeron filifolius. Proximal leaves are not clustered as a basal rosette; they are inserted on closely spaced nodes that are slightly more separated distally. Plants identified as var. robustior (with more ray florets, fewer heads, and thicker stems, centered in Oregon and Washington) intergrade with the typical form and apparently are separated arbitrarily. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
The population in Baja California is disjunct from the closest range in Arizona and northern Nevada. Plants glabrous and glandular on the phyllaries, stems, and leaves have been recognized as var. macranthus; they intergrade with hairier forms and do not show a coherent geographic pattern. Plants commonly identified as Erigeron subtrinervis var. conspicuus usually have stems sparsely hirsuto-pilose with hairs 1–1.5 mm, and the leaves commonly are ciliate on the margins and veins. As implied in the nomenclatural combination by Breitung, those plants are more similar to E. speciosus than to E. subtrinervis, and they apparently show part of the greater variability of E. speciosus in the northwestern part of its range (Alberta, British Columbia, Idaho, Montana, Oregon, Washington, and Wyoming), where more typical plants also occur. Erigeron speciosus and E. subtrinervis are sympatric over large parts of their ranges and appear to be at least partially reproductively isolated entities, although intermediates are frequently encountered. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 298. | FNA vol. 20, p. 330. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Diplopappus filifolius, E. filifolius var. robustior | Stenactis speciosa, E. conspicuus, E. macranthus, E. speciosus var. conspicuus, E. speciosus var. macranthus, E. subtrinervis subsp. conspicuus, E. subtrinervis var. conspicuus |
Name authority | (Hooker) Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 308. (1840) | (Lindley) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 284. (1836) |
Web links |
|