Erigeron caespitosus |
Erigeron cavernensis |
|
---|---|---|
tuft daisy, tuft fleabane |
lone fleabane |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | Perennials, 1–6 cm (cespitose); taprooted, caudex branches usually relatively slender, lignescent, sometimes relatively elongate. |
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. |
erect, sparsely to densely villous to hirsuto-villous, densely minutely glandular. |
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. |
all or mostly basal (persistent; petioles densely spreading-ciliate, cilia relatively thin-based); blades spatulate to oblanceolate-spatulate, 5–20(–28) × (1.5–)2–6 mm (bases abruptly contracted to petioles), margins entire, faces densely hirsuto-canescent, densely minutely glandular. |
Involucres | 4–7 × 9–18 mm. |
3.5–4.5 × 5–8(–10) mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
(12–)16–24; corollas white to pinkish or lavender, sometimes with faint pink or lavender abaxial midstripe, 4.5–6 mm, laminae weakly coiling. |
Disc corollas | 3–4.4 mm. |
1.9–2.1 mm. |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in 2(–3) series (often purplish,) sparsely hirsuto-villous, densely villous basally, evenly, densely 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. |
1–1.2 mm, 2-nerved, faces strigose; pappi: outer of setae, inner of (11–)13–20 bristles. |
2n | = 18, 36. |
|
Erigeron caespitosus |
Erigeron cavernensis |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Jul. |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Limestone ridges, outcrops, and cliffs, often with bristlecone pine, limber pine, spruce |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 2100–3400 m (6900–11200 ft) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
|
NV |
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.) |
Of conservation concern. Erigeron cavernensis has been treated as a synonym of E. uncialis (A. Cronquist 1994; G. L. Nesom 1992b); E. uncialis var. conjugans, which closely approaches E. cavernensis in its geographic range, is markedly different from the latter and perhaps more similar to E. cronquistii. Erigeron uncialis var. uncialis and E. uncialis var. conjugans, though different in vestiture, have more features in common among themselves and contrast as a unit with E. cavernensis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 306. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | S. L. Welsh & N. D. Atwood: Great Basin Naturalist 48: 495, fig. 1. (1988) |
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