Erigeron caespitosus |
Erigeron quercifolius |
|
---|---|---|
tuft daisy, tuft fleabane |
oak-leaf fleabane |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | |
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 to basally ascending (green proximally), proximally villous to villoso-hirsute, distally loosely strigose to hirsute, 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 oblanceolate to obovate or spatulate, 15–110(–150) × 4–25(–30) mm, margins serrate or crenate to pinnately lobed, faces hirsute to villous, eglandular; cauline blades becoming oblong, gradually reduced distally (reduced to bracts or 0 proximal to arrays, clasping to subclasping). |
Involucres | 4–7 × 9–18 mm. |
2.5–4 × 4.5–10 mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
100–150; corollas usually blue, sometimes white to pink, 4–6 mm, laminae not coiling or reflexing. |
Disc corollas | 3–4.4 mm. |
1.5–2.8 mm. |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in (2–)3–4 series (sometimes basally connate), strigose to hirsuto-villous, eglandular or sparsely minutely glandular. |
Heads | 1–4 (branches from distal 1/2 of stem). |
(1–)4–16(–50) in corymbiform arrays (from branches distal to midstem). |
Cypselae | 1.7–2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae or scales, inner of 15–25 bristles. |
0.6–0.9 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 10–15 bristles. |
Winter | annuals, biennials, or short-lived perennials, 10–60 cm; fibrous-rooted, caudices simple. |
|
2n | = 18, 36. |
= 18. |
Erigeron caespitosus |
Erigeron quercifolius |
|
Phenology | Flowering Jun–Aug. | Flowering (Feb–)Mar–Jun. |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Sandy sites, shell rock, roadsides, ditches, fields, areas of pine flatwoods |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 0–15 m (0–0 ft) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
|
FL; GA; NC; SC; VA; West Indies (Bahama Islands)
|
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 quercifolius is primarily of the Atlantic coastal plain. Putative records from Alabama westward to Texas are based on specimens of E. philadelphicus or E. tenuis. Erigeron tenuis sometimes closely approaches E. quercifolius in overall appearance; it is more closely related to E. strigosus. Convergent plants of E. tenuis differ from E. quercifolius in their non-clasping cauline leaves, lanceolate (versus oblanceolate to obovate) phyllaries, and slightly longer cypselae (1–1.2 mm versus 0.6–0.9 mm). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 320. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | Lamarck: in J. Lamarck and J. Poiret, Tabl. Encycl. 3: 258. (1796) |
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