Erigeron caespitosus |
Erigeron versicolor |
|
---|---|---|
tuft daisy, tuft fleabane |
bald-fruit fleabane, changing fleabane |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | Annuals or rarely short-lived perennials, 12–50(–80) cm; taprooted or rarely fibrous-rooted. |
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. |
(single or multiple from bases) usually basally ascending, strigose to villous, often slightly and minutely stipitate-glandular near to heads. |
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 (usually not persistent) and cauline; blades narrowly lanceolate to oblanceolate, basal (5–)20–50 × 3–9 mm, cauline gradually reduced distally, margins entire or proximal shallowly crenate to serrate with 1–3 pairs of teeth, faces sparsely strigose, eglandular. |
Involucres | 4–7 × 9–18 mm. |
2.5–4 × (3–)5–9 mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
60–110; corollas white, 2.5–5(–7) mm, laminae not reflexing or coiling. |
Disc corollas | 3–4.4 mm. |
1.2–2 mm (throats slightly indurate and inflated). |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in 2–3 series (margins scarious at least in inner), sparsely hirsute, minutely glandular. |
Heads | 1–4 (branches from distal 1/2 of stem). |
(1–)5–ca. 100. |
Cypselae | 1.7–2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae or scales, inner of 15–25 bristles. |
(0.5–)0.8–1.3 mm, 2-nerved, faces glabrous or sparsely strigose; pappi: outer of minute, blunt scales or fimbriate crowns (to 0.15 mm), inner 0. |
2n | = 18, 36. |
= 18, 27, 36. |
Erigeron caespitosus |
Erigeron versicolor |
|
Phenology | Flowering Jun–Aug. | Flowering Apr–Jun(–Oct). |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Scattered and local, open sites, usually in moist soil, edges of low or marshy areas, stream edges, ditches |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 100–400 m (2600–2900 m, Ariz.) (300–1300 ft (8500–9500 ft, Ariz.)) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
|
AZ; NM; TX; Mexico |
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.) |
In Arizona, Erigeron versicolor grows in meadows, along creeks, and in pine-aspen-spruce areas. Erigeron versicolor is distinguished by its annual duration, nodding buds, conic receptacles, broad phyllaries, and pappi of only minute crowns. The species appears to be disjunctly divided among three regions in the United States and Mexico (D. C. D. De Jong and G. L. Nesom 1996), and habitats vary widely. This is an unusual distribution. There is much variation in duration, root type, orientation of stem pubescence, elaboration of the pappus crown, and achene vestiture, and this morphologic variation does not appear to be strongly correlated with geography. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 344. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Achaetogeron versicolor, Achaetogeron chihuahuensis, E. geiseri var. calcicola, E. gilensis, E. mimegletes | |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | (Greenman) G. L. Nesom: Sida 9: 225. (1982) |
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