Erigeron nivalis |
Erigeron denalii |
|
---|---|---|
bitter daisy, bitter fleabane, northern daisy, snow fleabane, snow fleabane daisy, snowbed fleabane |
Denali fleabane |
|
Habit | Biennials or short-lived perennials, 5–25(–35) cm; usually fibrous-rooted, sometimes taprooted, caudices simple or branched, sometimes weakly short-rhizomatous. | Perennials, 1–5 cm; taprooted, caudices diffuse with extensive systems of rhizomelike, relatively long and slender branches. |
Stems | erect to basally ascending, sometimes sparsely hirsuto-villous, minutely glandular. |
erect (simple, ± scapiform), villous, granular-glandular. |
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; blades spatulate to oblanceolate-spatulate, 10–20 × 2–4(–5) mm, mid larger than basal and proximal, margins entire or shallowly (2–)3-lobed or -toothed apically (apices obtuse to nearly truncate), faces moderately villous, minutely glandular. |
Involucres | 5–6 × 8–11 mm. |
(4–)5–7 × 9–12 mm. |
Ray florets | 30–55; corollas white to lavender, 4–8 mm, laminae (filiform to narrowly straplike, 0.3–2 mm wide, often involute) erect, rarely spreading, not coiling or reflexing. |
|
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 florets/ |
4.4–5.5 mm. |
3.8–4.8 mm. |
Phyllaries | in 2–3(–4) series (inner apices attenuate to caudate), sparsely hirsuto-villous or glabrous, minutely glandular. |
in 2(–3) series, densely lanate-villous (hairs to 3 mm, often with dark purple cross walls), 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. |
3–3.8 mm, 2-nerved, faces strigillose to strigoso-hirsute; pappi: outer 0 (or inconspicuous), inner of 20–25 (usually ± purple-red tinged, sometimes whitish, variable within populations) bristles. |
2n | = 18. |
|
Erigeron nivalis |
Erigeron denalii |
|
Phenology | Flowering May–Aug. | Flowering Jun–Aug. |
Habitat | Rocky sites, gravel bars and banks, roadsides, meadows, open woods, up to subalpine areas with spruce in Rocky Mountains | Open alpine and subalpine habitats, tundra slopes, openings in spruce-fir woods, gravelly and shaley scree, cut banks |
Elevation | 1200–3700 m (3900–12100 ft) | 900–2200 m (3000–7200 ft) |
Distribution |
AK; CA; CO; ID; MT; NM; OR; UT; WA; WY; AB; BC; NT; YT
|
AK; NT; YT; BC |
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 denalii and E. purpuratus are similar and probably closely related; the two appear to be partially sympatric; differences in vestiture and leaf morphology are constant. The habitat of E. purpuratus, sandy or gravelly alluvium, also is remarkably constant and distinct from that of E. denalii. Apparently correlated with the habitat, plants of E. purpuratus almost always develop a relatively long and slender, woody taproot; taproots of E. denalii apparently are less well defined and often are not collected. Plants of the type collection of Erigeron mexiae have ray corollas with relatively broad laminae (1.5–2 mm wide); ray corolla width is variable in E. denalii, and E. mexiae is regarded here as an extreme variant within the species. In other characters, there appears to be no difference. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 322. | FNA vol. 20, p. 303. |
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. mexiae, E. purpuratus var. dilatatus |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 311. (1841) | A. Nelson: Amer. J. Bot. 32: 289. (1945) |
Web links |
|
|