Erigeron speciosus |
Erigeron neomexicanus |
|
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aspen fleabane, showy daisy, showy fleabane, splendid fleabane |
New Mexico fleabane |
|
Habit | Perennials, 30–80(–100) cm; rhizomatous, fibrous-rooted, caudices relatively thick. | Perennials, 20–70 cm; taprooted, caudices woody. |
Stems | erect, glabrous or sparsely hirsuto-pilose (hairs 0.5–1 mm), often minutely glandular distally. |
erect, moderately to densely strigose (hairs appressed to ascending, 0.1–0.8(–2) mm, sometimes spreading at bases or throughout), eglandular or glands minute, non-capitate. |
Leaves | 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). |
basal (sometimes persistent) and cauline; blades oblanceolate, margins usually deeply pinnatifid (lobes in 2–5 pairs), sometimes dentate to entire, faces strigose, eglandular; basal 10–60 × 6–35 mm, cauline gradually reduced distally. |
Involucres | 6–9 × 11–22 mm. |
3.5–5 × 7–12 mm. |
Ray florets | 75–150; corollas blue to lavender, rarely whitish, 8–16 mm (mostly 1 mm wide), laminae slightly coiling at least at tips. |
70–150; corollas white, drying white, (2–)6–15 mm, laminae reflexing. |
Disc corollas | 4–5 mm. |
2.5–3.3 mm (throats somewhat white-indurate, not inflated). |
Phyllaries | in 2–3(–4) series, usually glabrous, sometimes sparsely hirsuto-pilose, minutely glandular. |
in 3–4 series, strigose to hirsute (hairs arising mostly from midregion), usually minutely glandular, rarely eglandular. |
Heads | (2–)4–20 in corymbiform arrays. |
(1–)5–15(–30) in loosely corymbiform arrays. |
Cypselae | 1.5–1.8 mm, 2(–4)-nerved, faces sparsely strigose; pappi: outer of setae, inner of 20–30 bristles. |
1–1.3 mm, 2(–4)–nerved, faces sparsely strigose; pappi: (outer 0) inner (readily falling) of (8–)10–12 bristles. |
2n | = 18, 36. |
|
Erigeron speciosus |
Erigeron neomexicanus |
|
Phenology | Flowering Jul–Oct. | Flowering (Jul–)Aug–Oct(–Dec). |
Habitat | Dry or moist, gravelly or loamy soil, prairies, yellow pine, pine-fir, spruce-fir, aspen-spruce | Open, rocky sites, from grasslands into oak or pine woodlands, often with madrono, juniper, or fir |
Elevation | (600–)900–3400 m ((2000–)3000–11200 ft) | (900–)1500–2700(–3000) m ((3000–)4900–8900(–9800) ft) |
Distribution |
AZ; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; Mexico (Baja California)
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AZ; NM; Mexico (Chihuahua, Sonora)
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Discussion | 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.) |
Relatively large, pinnatifid leaves are typical of Erigeron neomexicanus; plants with nearly entire leaves can be identified by the strongly perennial habit, white, reflexing rays, and 10–12 readily falling pappus bristles. Erigeron neomexicanus and E. oreophilus were treated by A. Cronquist (1947) as varieties of one species, and their morphologic similarity and the closeness of their geographic ranges support that hypothesis. But relatively few collections are found that could be regarded as intermediates, and both forms sometimes grow in proximity, apparently without a range of intermediates. In some Arizona mountain ranges, apparently only one or the other taxon occurs. Still, the possibility exists that these are populational segregants of a single species (see further comments in G. L. Nesom 1989d). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 330. | FNA vol. 20, p. 277. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Stenactis speciosa, E. conspicuus, E. macranthus, E. speciosus var. conspicuus, E. speciosus var. macranthus, E. subtrinervis subsp. conspicuus, E. subtrinervis var. conspicuus | E. delphiniifolius var. euneomexicanus, E. delphiniifolius subsp. neomexicanus |
Name authority | (Lindley) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 284. (1836) | A. Gray: Proc. Amer. Acad. Arts 19: 2. (1883) |
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