Erigeron caespitosus |
Erigeron modestus |
|
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tuft daisy, tuft fleabane |
plains fleabane |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | Perennials (sometimes flowering early and appearing annual or biennial), 8–40 cm; usually taprooted (taproots woody or lignescent, early season forms sometimes fibrous-rooted), caudices usually woody, sometimes 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. |
(often multiple from bases; of previous year often persistent) ascending to spreading (proximally reddish in early season, sometimes proximally woody or lignescent), loosely strigose to villous (proximal hairs sometimes spreading), often sparsely 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. |
basal (often withering by late flowering) and cauline; blades oblanceolate to spatulate, 20–50(–100) × 3–7(–18) mm, gradually reduced distally, margins entire or with 1–2(–3) pairs of teeth, faces loosely strigose (hairs ascending), eglandular. |
Involucres | 4–7 × 9–18 mm. |
3–4.5 × 6–9(–12) mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
24–65(–170); corollas white, often with abaxial midstripe, often drying lilac, 4–7(–11) mm, laminae not coiling or reflexing. |
Disc corollas | 3–4.4 mm. |
1.7–3.1 mm (throats indurate and slightly inflated). |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in 2–3 series, sparsely to moderately hirsute, minutely glandular. |
Heads | 1–4 (branches from distal 1/2 of stem). |
1(–3+, –50 in later season, branches at first from midstem or proximally, later more distal). |
Cypselae | 1.7–2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae or scales, inner of 15–25 bristles. |
1.1–1.4 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of (5–)12–17 bristles. |
2n | = 18, 36. |
= 27, 36. |
Erigeron caespitosus |
Erigeron modestus |
|
Phenology | Flowering Jun–Aug. | Flowering (Mar–)Apr–Jun(–Oct). |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Rocky or gravelly sites, sand, clay, limestone, granite, sometimes deep sand, often with oak or oak-juniper, shrubland |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 200–1700(–2300) m (700–5600(–7500) ft) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
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AZ; KS; NM; OK; TX; Mexico (Coahuila, Chihuahua, Nuevo Leon)
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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 modestus is a polyploid complex apparently incorporating genes from E. flagellaris, E. tracyi, elements of E divergens, and the Mexican E. pubescens Kunth; arbitrary identifications may be necessary. In most of its range in Texas, E. modestus is not sympatric with any of those other taxa. Forms flowering in early season (Mar–Apr) often have stems red at the bases, dentate basal leaves 30–60(–100) × 5–10(–18) mm, and single, relatively large heads (involucres 9–12 mm diam, ray florets 50–170, corollas 6.5–11 mm) on ebracteate peduncles 5–15 cm. Later season plants have nearly intricately branched stems with more numerous, much smaller, diffusely arranged heads. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 341. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. lobatus var. warnockii, E. plateauensis, E. warnockii | |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 68. (1849) |
Web links |