Erigeron neomexicanus |
Erigeron nivalis |
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New Mexico fleabane |
bitter daisy, bitter fleabane, northern daisy, snow fleabane, snow fleabane daisy, snowbed fleabane |
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Habit | Perennials, 20–70 cm; taprooted, caudices woody. | Biennials or short-lived perennials, 5–25(–35) cm; usually fibrous-rooted, sometimes taprooted, caudices simple or branched, sometimes weakly short-rhizomatous. |
Stems | 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. |
erect to basally ascending, sometimes sparsely hirsuto-villous, minutely glandular. |
Leaves | 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. |
basal (persistent) and cauline (petiole margins coarsely ciliate); basal blades oblanceolate to spatulate, 20–60 × 2–6(–10) mm; cauline gradually reduced distally, margins entire or rarely with 1–2 pairs of shallow teeth, faces sparsely hirsuto-strigose, eglandular. |
Involucres | 3.5–5 × 7–12 mm. |
5–6 × 8–11 mm. |
Ray florets | 70–150; corollas white, drying white, (2–)6–15 mm, laminae reflexing. |
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Ray (pistillate) florets | in 2 series; outer 40–70, corollas white to pinkish 5.5–7 mm, laminae (filiform) erect, not coiling or reflexing; inner many fewer than outer series, tubular, elaminate. |
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Disc corollas | 2.5–3.3 mm (throats somewhat white-indurate, not inflated). |
4.4–5.5 mm. |
Phyllaries | in 3–4 series, strigose to hirsute (hairs arising mostly from midregion), usually minutely glandular, rarely eglandular. |
in 2–3(–4) series (inner apices attenuate to caudate), sparsely hirsuto-villous or glabrous, minutely glandular. |
Heads | (1–)5–15(–30) in loosely corymbiform arrays. |
1–6(–8) in corymbiform arrays (on curved-ascending peduncles). |
Cypselae | 1–1.3 mm, 2(–4)–nerved, faces sparsely strigose; pappi: (outer 0) inner (readily falling) of (8–)10–12 bristles. |
2–2.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of (12–)14–21 (accrescent) bristles. |
2n | = 18, 36. |
= 18. |
Erigeron neomexicanus |
Erigeron nivalis |
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Phenology | Flowering (Jul–)Aug–Oct(–Dec). | Flowering May–Aug. |
Habitat | Open, rocky sites, from grasslands into oak or pine woodlands, often with madrono, juniper, or fir | Rocky sites, gravel bars and banks, roadsides, meadows, open woods, up to subalpine areas with spruce in Rocky Mountains |
Elevation | (900–)1500–2700(–3000) m ((3000–)4900–8900(–9800) ft) | 1200–3700 m (3900–12100 ft) |
Distribution |
AZ; NM; Mexico (Chihuahua, Sonora)
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AK; CA; CO; ID; MT; NM; OR; UT; WA; WY; AB; BC; NT; YT
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Discussion | 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.) |
Erigeron nivalis usually has been treated as an infra-specific taxon within E. acris; the two are broadly sympatric in the northwestern United States and Canada without obvious intergrades. Both occur over a wide range of elevations and in similar habitats. Erigeron nivalis probably occurs in Nevada; it has not been taxonomically distinguished there. Erigeron scotteri was regarded by E. H. Moss and J. G. Packer (1983) as a synonym of E. acris (presumably var. debilis = E. nivalis; the heads are relatively small and borne singly). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 277. | FNA vol. 20, p. 322. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. delphiniifolius var. euneomexicanus, E. delphiniifolius subsp. neomexicanus | E. acris subsp. debilis, E. acris var. debilis, E. angulosus subsp. debilis, E. debilis, E. elatus var. bakeri, E. jucundus, E. scotteri, Trimorpha acris var. debilis |
Name authority | A. Gray: Proc. Amer. Acad. Arts 19: 2. (1883) | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 311. (1841) |
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