Erigeron caespitosus |
Erigeron gracilis |
|
---|---|---|
tuft daisy, tuft fleabane |
quill fleabane |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | Perennials, 5–20 cm; rhizomatous, fibrous-rooted, forming diffuse systems of slender, rhizomelike caudex branches. |
Stems | decumbent-ascending (greenish proximally), usually densely hirsute to hirtellous (hairs spreading to deflexed, gradually attenuate, basal cells erect), sometimes strigose (in Saskatchewan and Yukon), eglandular. |
ascending (bases usually purplish), glabrous or sparsely strigose (or hairs loosely spreading), eglandular. |
Leaves | basal (persistent) and cauline; basal blades (1–)3-nerved, narrowly oblanceolate to spatulate, (10–)20–90(–120) × 2–15 mm, margins entire (apices rounded to obtuse), faces densely hirtellous, eglandular; cauline blades oblong-ovate to linear, ± reduced distally. |
basal (persistent) and cauline; basal (purplish) and proximal cauline blades oblanceolate to oblong, 20–40(–90) × 1–3(–5) mm, cauline reduced distally, margins entire, glabrous or sparsely strigose (or hairs loosely spreading), eglandular. |
Involucres | 4–7 × 9–18 mm. |
5–7.5 × 10–15 mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
40–100; corollas blue to pinkish purple, 7–14 mm, laminae not coiling or reflexing. |
Disc corollas | 3–4.4 mm. |
4.1–5.6 mm. |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in 2–3(–4) series (margins and tips often purplish, loose, linear-lanceolate, apices spreading), sparsely strigoso-hirsute to strigose (hairs appressed or slightly loose), sometimes minutely glandular. |
Heads | 1–4 (branches from distal 1/2 of stem). |
1. |
Cypselae | 1.7–2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae or scales, inner of 15–25 bristles. |
2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 14–21 bristles. |
2n | = 18, 36. |
= 18. |
Erigeron caespitosus |
Erigeron gracilis |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Moist slopes, creek bottoms, sagebrush meadows |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 2200–2400 m (7200–7900 ft) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
|
ID; MT; WY
|
Discussion | Erigeron caespitosus as recognized here is highly variable and perhaps justifiably could be divided into more than one taxon. Plants at lower elevations tend to produce tall stems branching above the middle and long, white rays. At higher elevations, especially in Idaho, western Montana, Utah, and Wyoming, stems tend to be shorter and simple and the rays commonly are blue to violet. In the Bitterroot Mountains (Ravalli and Deerlodge counties, Montana), short-stemmed, blue-rayed plants also have strigose cauline vestiture (in contrast to typically deflexed-hirtellous stems); these vestiture variants occur in the same area with plants apparently similar in all other features. Strigose populational variants also occur in Saskatchewan and Yukon, and E. abajoensis, largely distinguished by strigose cauline vestiture, might be considered a regional variant of E. caespitosus. In eastern Idaho and southwestern Montana, plants of E. caespitosus are commonly encountered with cauline leaves obovate and distinctly subclasping. Plants with strongly 3-nerved basal leaves occur in Carbon and Gallatin counties, Montana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Erigeron gracilis “differs from E. ursinus in the strigose and scarcely glandular pubescence of the involucre, narrower and less herbaceous phyllaries, narrower and on the average longer disc-corollas, simple or nearly simple pappus, narrower ligules, on the average, and ordinarily narrower and slightly hairier leaves. E. gracilis grows at lower elevations than E. ursinus, in a drier habitat, and has a much more restricted range” (A. Cronquist 1947, p. 162). The two species are sympatric in northwestern Wyoming. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 336. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. ursinus var. gracilis | |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | Rydberg: Mem. New York Bot. Gard. 1: 404. (1900) |
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