Erigeron caespitosus |
Erigeron parryi |
|
---|---|---|
tuft daisy, tuft fleabane |
Parry's fleabane |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | Perennials, 1.5–5(–15) cm; taprooted, caudices multicipital or with relatively short, thick 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. |
erect, usually hirsute, rarely loosely strigoso-villous, 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 blades linear-oblanceolate, 10–25(–50) × 0.8–2 mm; cauline on proximal 1/2–2/3 of stems, gradually reduced distally, margins entire, eciliate (apices rounded to obtuse), faces equally, densely loosely strigose to hirsuto-strigose, eglandular. |
Involucres | 4–7 × 9–18 mm. |
4–7 × 7–10 mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
20–40; corollas white to pink or bluish, 6–8 mm, laminae not coiling or reflexing. |
Disc corollas | 3–4.4 mm. |
2.4–3.5 mm. |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in (2–)3 series (subequal), sparsely to densely villoso-strigose (basal cross walls sometimes purple), sparsely minutely glandular. |
Heads | 1–4 (branches from distal 1/2 of stem). |
1(–3, rarely). |
Cypselae | 1.7–2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae or scales, inner of 15–25 bristles. |
2–2.3 mm, 2-nerved, faces densely strigose; pappi: outer of setae or scales, inner of 12–15 (readily falling) bristles. |
2n | = 18, 36. |
|
Erigeron caespitosus |
Erigeron parryi |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Open, rocky (limestone) slopes and ridgecrests, sagebrush |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 1300–2200 m (4300–7200 ft) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
|
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 parryi mostly has been included within the concept of E. ochroleucus, but two studies (P. Lesica 2005; G. L. Nesom 2004e) independently have confirmed its reality as an endemic of southwestern Montana and adjacent Wyoming. Leaves of E. parryi are equally hairy (usually hirsuto-strigose) on both faces, contrasted with the reduced vestiture (loosely strigose) only on adaxial leaf faces of E. ochroleucus, and the involucral vestiture is of hairs often with purplish cross walls. Also, E. parryi produces branched caudices and smaller heads with fewer rays. Lesica also noted as distinctive the caudex branches thickened by the presence of old leaf bases proximal to the current leaves. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 293. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | Canby & Rose: Bot. Gaz. 15: 65. (1890) |
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