Erigeron radicatus |
Erigeron porsildii |
|
---|---|---|
Hooker's fleabane, Huber's fleabane, tap-root fleabane |
Porsild's arctic fleabane |
|
Habit | Perennials, (1–)2–6(–12) cm; taprooted, caudices branches relatively short, thick. | Perennials, (2–)10–20(–25) cm; rhizomatous, fibrous-rooted, rhizomes horizontal or erect, sometimes branched, relatively short, sometimes resembling taproots. |
Stems | erect, strigose to sparsely or densely short-villous (hairs loosely appressed to ascending or spreading), eglandular. |
erect, sparsely to moderately villous (hairs 0.5–1.6 mm), usually stipitate-glandular (hairs 0.05–0.4 mm). |
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; 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 | (3–)4–6(–8) × (5–)8–12(–15) mm. |
6–10 × 12–20 mm. |
Ray florets | (12–)20–44(–85); corollas white, less commonly purplish, 4–7(–8) mm, laminae coiling. |
65–110; corollas white to lavender or blue, 13–17 mm (1.2–1.7 mm wide), laminae weakly coiling. |
Disc corollas | (2–)2.5–3.5(–4) mm. |
3.8–4.5 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 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. |
1. |
Cypselae | 2.1–2.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of scales, inner of (6–)7–11 (readily falling) bristles. |
2–2.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of relatively long setae or scales, inner of 14–20(–25) bristles. |
2n | = 36. |
|
Erigeron radicatus |
Erigeron porsildii |
|
Phenology | Flowering May–Aug. | Flowering (Jun–)Jul–Aug(–Sep). |
Habitat | Rocky slopes, ridges, and summits, ledges and crevices, outcrops and talus, usually limestone, alpine tundra | Cliffs and talus (often calcareous) slopes, shaley gravel, grassy ravines, dry tundra |
Elevation | (1400–)1600–2800(–3400) m ((4600–)5200–9200(–11200) ft) | 600–2100 m (2000–6900 ft) |
Distribution |
CO; ID; MT; ND; NE; SD; UT; WY; AB; SK
|
AK; NT; YT |
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 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. 294. | FNA vol. 20, p. 324. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. huberi, E. macounii | E. grandiflorus subsp. arcticus |
Name authority | Hooker: Fl. Bor.-Amer. 2: 17, plate 122. (1834) | G. L. Nesom & D. F. Murray: Sida 21: 44. (2004) |
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