Erigeron filifolius |
Erigeron versicolor |
|
---|---|---|
Peck's threadleaf fleabane, thread-leaf daisy, thread-leaf fleabane |
bald-fruit fleabane, changing fleabane |
|
Habit | Perennials, 10–30(–50) cm; taprooted, caudices multicipital, often with relatively short and thin, stemlike, lignescent branches. | Annuals or rarely short-lived perennials, 12–50(–80) cm; taprooted or rarely fibrous-rooted. |
Stems | erect, sparsely to densely strigose (hairs loosely appressed to ascending, fine), densely white-strigose at least proximally, eglandular. |
(single or multiple from bases) usually basally ascending, strigose to villous, often slightly and minutely stipitate-glandular near to heads. |
Leaves | basal (usually persistent, not clustered as rosettes) and cauline; basal blades linear to filiform, 10–80 × 0.5–2.5(–3.5) mm; cauline gradually or little reduced distally, margins entire, faces sparsely to moderately strigose, eglandular. |
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 × 5–-18 mm. |
2.5–4 × (3–)5–9 mm. |
Ray florets | (15–)20–125; corollas usually blue, sometimes white, pink, or pale lavender, 3–13 mm, laminae coiling. |
60–110; corollas white, 2.5–5(–7) mm, laminae not reflexing or coiling. |
Disc corollas | 2.5–5.5 mm. |
1.2–2 mm (throats slightly indurate and inflated). |
Phyllaries | in (2–)3–4 series, loosely strigose to hirsute or nearly villous, densely to sparsely minutely glandular. |
in 2–3 series (margins scarious at least in inner), sparsely hirsute, minutely glandular. |
Heads | 1–5(–10+) from distal branches, tending to be in corymbiform arrays. |
(1–)5–ca. 100. |
Cypselae | 1.4–1.8(–2) mm, 2-nerved, faces sparsely strigose to glabrate; pappi: outer of setae, inner of 20–30 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. |
= 18, 27, 36. |
Erigeron filifolius |
Erigeron versicolor |
|
Phenology | Flowering May–Aug. | Flowering Apr–Jun(–Oct). |
Habitat | Dry, rocky or sandy soil, lava beds, bitterbrush, sagebrush, juniper, ponderosa pine | Scattered and local, open sites, usually in moist soil, edges of low or marshy areas, stream edges, ditches |
Elevation | 400–2400 m (1300–7900 ft) | 100–400 m (2600–2900 m, Ariz.) (300–1300 ft (8500–9500 ft, Ariz.)) |
Distribution |
CA; ID; MT; NV; OR; UT; WA; BC
|
AZ; NM; TX; Mexico |
Discussion | The densely white-strigose stem bases, linear-filiform leaves relatively unreduced distally, and relatively few heads with coiling, usually blue rays are distinctive for Erigeron filifolius. Proximal leaves are not clustered as a basal rosette; they are inserted on closely spaced nodes that are slightly more separated distally. Plants identified as var. robustior (with more ray florets, fewer heads, and thicker stems, centered in Oregon and Washington) intergrade with the typical form and apparently are separated arbitrarily. (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. 298. | FNA vol. 20, p. 344. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Diplopappus filifolius, E. filifolius var. robustior | Achaetogeron versicolor, Achaetogeron chihuahuensis, E. geiseri var. calcicola, E. gilensis, E. mimegletes |
Name authority | (Hooker) Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 308. (1840) | (Greenman) G. L. Nesom: Sida 9: 225. (1982) |
Web links |
|