Erigeron nivalis |
Erigeron porsildii |
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bitter daisy, bitter fleabane, northern daisy, snow fleabane, snow fleabane daisy, snowbed fleabane |
Porsild's arctic fleabane |
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Habit | Biennials or short-lived perennials, 5–25(–35) cm; usually fibrous-rooted, sometimes taprooted, caudices simple or branched, sometimes weakly short-rhizomatous. | Perennials, (2–)10–20(–25) cm; rhizomatous, fibrous-rooted, rhizomes horizontal or erect, sometimes branched, relatively short, sometimes resembling taproots. |
Stems | erect to basally ascending, sometimes sparsely hirsuto-villous, minutely glandular. |
erect, sparsely to moderately villous (hairs 0.5–1.6 mm), usually stipitate-glandular (hairs 0.05–0.4 mm). |
Leaves | 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. |
basal (persistent) and cauline; basal blades oblong-oblanceolate to narrowly obovate, 30–120 × (3–)5–14 mm, margins entire (apices acute), faces densely hirsute to coarsely villous, sparsely stipitate-glandular to minutely glandular; cauline blades oblong-lanceolate to lanceolate, gradually reduced distally or nearly equal-sized (bases often subclasping). |
Involucres | 5–6 × 8–11 mm. |
6–10 × 12–20 mm. |
Ray florets | 65–110; corollas white to lavender or blue, 13–17 mm (1.2–1.7 mm wide), laminae weakly coiling. |
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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. |
|
Disc corollas | 4.4–5.5 mm. |
3.8–4.5 mm. |
Phyllaries | in 2–3(–4) series (inner apices attenuate to caudate), sparsely hirsuto-villous or glabrous, minutely glandular. |
in ca. 2 series (purple at least at tips, narrowly lanceolate, equal, apically acuminate), densely hirsute, hirsuto-villous, or villous (hairs whitish, cross walls not colored), sparsely stipitate-glandular to minutely glandular. |
Heads | 1–6(–8) in corymbiform arrays (on curved-ascending peduncles). |
1. |
Cypselae | 2–2.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of (12–)14–21 (accrescent) bristles. |
2–2.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of relatively long setae or scales, inner of 14–20(–25) bristles. |
2n | = 18. |
= 36. |
Erigeron nivalis |
Erigeron porsildii |
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Phenology | Flowering May–Aug. | Flowering (Jun–)Jul–Aug(–Sep). |
Habitat | Rocky sites, gravel bars and banks, roadsides, meadows, open woods, up to subalpine areas with spruce in Rocky Mountains | Cliffs and talus (often calcareous) slopes, shaley gravel, grassy ravines, dry tundra |
Elevation | 1200–3700 m (3900–12100 ft) | 600–2100 m (2000–6900 ft) |
Distribution |
AK; CA; CO; ID; MT; NM; OR; UT; WA; WY; AB; BC; NT; YT
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AK; NT; YT |
Discussion | 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.) |
Erigeron hultenii S. A. Spongberg was noted to be “closely allied to the polymorphic arctic-alpine species E. grandiflorus W. J. Hooker” (S. A. Spongberg 1973, p. 116) and to have a “close morphologic resemblance to some plants of E. grandiflorus from Alaska” [E. porsildii in the present sense] (p. 119). Plants corresponding to E. hultenii have not been recollected, and that taxon does not fit with any other known Alaskan species. Contrasts with E. porsildii exclude it from that species. Erigeron hultenii is not recognized formally herein. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 322. | FNA vol. 20, p. 324. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | 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 | E. grandiflorus subsp. arcticus |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 311. (1841) | G. L. Nesom & D. F. Murray: Sida 21: 44. (2004) |
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