Erigeron radicatus |
Erigeron nivalis |
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Hooker's fleabane, Huber's fleabane, tap-root fleabane |
bitter daisy, bitter fleabane, northern daisy, snow fleabane, snow fleabane daisy, snowbed fleabane |
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Habit | Perennials, (1–)2–6(–12) cm; taprooted, caudices branches relatively short, thick. | Biennials or short-lived perennials, 5–25(–35) cm; usually fibrous-rooted, sometimes taprooted, caudices simple or branched, sometimes weakly short-rhizomatous. |
Stems | erect, strigose to sparsely or densely short-villous (hairs loosely appressed to ascending or spreading), eglandular. |
erect to basally ascending, sometimes sparsely hirsuto-villous, minutely glandular. |
Leaves | mostly basal (persistent) (eciliate or weakly ciliate proximally); blades 1-nerved linear to narrowly oblanceolate or subspatulate, (5–)10–50(–60) × 0.8–2.5 mm (bases gradually narrowing), margins entire (apices obtuse to rounded), abaxial faces glabrate or glabrous, shiny, adaxial sparsely, loosely strigose, eglandular; cauline mostly on proximal 1/2–1/3 of stems (absent in some high elevation forms), abruptly or 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–)4–6(–8) × (5–)8–12(–15) mm. |
5–6 × 8–11 mm. |
Ray florets | (12–)20–44(–85); corollas white, less commonly purplish, 4–7(–8) mm, laminae 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. |
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Disc corollas | (2–)2.5–3.5(–4) mm. |
4.4–5.5 mm. |
Phyllaries | in 2–3(–4) series (subequal), villosulous to villoso-hirsutulous (hairs usually with purplish cross walls at least in basal cells), minutely glandular apically or eglandular. |
in 2–3(–4) series (inner apices attenuate to caudate), sparsely hirsuto-villous or glabrous, minutely glandular. |
Heads | 1. |
1–6(–8) in corymbiform arrays (on curved-ascending peduncles). |
Cypselae | 2.1–2.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of scales, inner of (6–)7–11 (readily falling) bristles. |
2–2.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of (12–)14–21 (accrescent) bristles. |
2n | = 18. |
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Erigeron radicatus |
Erigeron nivalis |
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Phenology | Flowering May–Aug. | Flowering May–Aug. |
Habitat | Rocky slopes, ridges, and summits, ledges and crevices, outcrops and talus, usually limestone, alpine tundra | Rocky sites, gravel bars and banks, roadsides, meadows, open woods, up to subalpine areas with spruce in Rocky Mountains |
Elevation | (1400–)1600–2800(–3400) m ((4600–)5200–9200(–11200) ft) | 1200–3700 m (3900–12100 ft) |
Distribution |
CO; ID; MT; ND; NE; SD; UT; WY; AB; SK
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AK; CA; CO; ID; MT; NM; OR; UT; WA; WY; AB; BC; NT; YT
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Discussion | Collections of Erigeron radicatus often have been identified as E. ochroleucus var. scribneri; E. radicatus is distinctive in its branched caudex, villous cauline vestiture, more reduced leaf vestiture, involucral vestiture of hairs with purple cross walls, shorter disc corollas, and relatively few, readily falling pappus bristles. Erigeron radicatus often is essentially scapiform at relatively high elevation (2700–3400 m) in Idaho, Montana, Utah, and Wyoming; more eastern populations in the Great Plains, at lower elevations (1400–2600 m), have leafier stems but are hardly different in other features. Plants of some populations in Albany and Carbon counties, Wyoming, produce atypically shorter rays. (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. 294. | FNA vol. 20, p. 322. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. huberi, E. macounii | 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 | Hooker: Fl. Bor.-Amer. 2: 17, plate 122. (1834) | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 311. (1841) |
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