Erigeron flagellaris |
Erigeron tracyi |
|
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trailing fleabane, whiplash daisy |
running fleabane |
|
Habit | Annuals, biennials, or short-lived perennials, 2.5–8(–12, 18) cm; usually taprooted, sometimes fibrous-rooted, caudices simple or branched. | |
Stems | first erect (greenish proximally; usually single, simple), then producing herbaceous, leafy, prostrate runners (usually with rooting plantlets at tips, populations often becoming clonal mats), strigose (often sparsely; hairs antrorsely appressed, consistent in orientation), sometimes slightly glandular distally. |
first erect (greenish proximally), then producing herbaceous, leafy, prostrate runners (stoloniform branches, sometimes with rooting plantlets at tips), densely hirsutulous (hairs spreading-deflexed, of relatively even lengths and orientations), sparsely minutely glandular. |
Leaves | basal (often persistent) and cauline; basal blades broadly oblanceolate to elliptic, 20–55 × 3–9 mm; cauline abruptly reduced distally, margins entire or dentate, faces strigose, eglandular. |
mostly basal (persistent in early season); blades oblanceolate to spatulate (obovate-elliptic laminae), 10–30(–60) × 3–6(–12) mm, cauline abruptly reduced distally, margins entire, dentate, or lobed, faces densely hirsute, eglandular. |
Involucres | 3–5 × 6–13 mm. |
3.5–4.5(–6) × 6–9(–12) mm. |
Ray florets | 40–125; corollas white, often with an abaxial midstripe, often drying lilac, 4–10 mm, laminae not coiling or reflexing. |
60–130; corollas white, often purplish abaxially, sometimes with an abaxial midstripe, 5–9 mm, laminae not coiling or reflexing. |
Disc corollas | 2–3.5 mm. |
2–3 mm (throats indurate and slightly inflated). |
Phyllaries | in 2–3 series, strigose to loosely hirsute, minutely glandular. |
in 3–4 series, sparsely to moderately hirsute, minutely glandular. |
Heads | 1(–3, on proximal branches). |
1(–3 rarely, from midstem or proximal branches). |
Cypselae | 0.8–1.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 10–17 bristles. |
0.7–1.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 12–16 bristles. |
Biennuals | or short-lived perennials, 3–15 cm; usually fibrous-rooted, sometimes taprooted, caudices lignescent, rarely branched. |
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2n | = 18, 27, 36, 45, 54. |
= 27. |
Erigeron flagellaris |
Erigeron tracyi |
|
Phenology | Flowering May–Aug(–Sep). | Flowering Mar–Oct. |
Habitat | Meadows and grassy slopes, often moist, open areas in grasslands, pinyon pine, oak-pine, pine, aspen, and spruce-fir | Desert scrub, grassy slopes, oak chaparral, pinyon-juniper woodlands, Douglas fir-ponderosa pine |
Elevation | (1700–)2100–3600 m ((5600–)6900–11800 ft) | 700–2300(–2400) m (2300–7500(–7900) ft) |
Distribution |
AZ; CA; CO; ID; KS; MT; ND; NE; NM; NV; OK; OR; SD; TX; UT; WA; WY; AB; BC; Mexico
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AZ; CO; KS; NM; NV; OK; TX; UT; Mexico (Baja California, Chihuahua, Coahuila, Durango, Sonora, Zacatecas)
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Discussion | Early season forms of Erigeron flagellaris may consist of a basal rosette and a single, erect, scapiform, monocephalous stem; leafy runners usually develop quickly. Many polyploids of this species are indistinguishable from diploids; some polyploids have features suggestive of genetic influence of E. tracyi. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
In March through June, plants of Erigeron tracyi produce leaves in a basal rosette usually with a single, erect, monocephalous, stem. Stoloniform branches are soon formed (often recognized on pressed specimens by the leaves mostly on one side of the branches), and by the end of the season (August through October), prostrate runners are usually evident, sometimes forming terminal, rooting plantlets. Erigeron tracyi is similar in habit to E. flagellaris, particularly in the herbaceous stolons or stoloniform branches; the stem pubescence of E. tracyi is different, the stolons much less commonly produce rooting plantlets at the tips, and the plants tend to be perennial with woody or lignescent caudices, although they are variable both in habit and duration. Apparent hybrids with E. modestus and E. flagellaris are occasionally encountered, and the most common form of E. tracyi is perhaps (speculative) a stabilized, apomictic hybrid between the latter and E. divergens. All chromosome counts thus far have shown E. tracyi to be triploid and asynaptic. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 341. | FNA vol. 20, p. 340. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. nudiflorus | E. cinereus, E. colomexicanus, E. commixtus, E. divergens var. cinereus |
Name authority | A. Gray: Mem. Amer. Acad. Arts, n. s. 4: 68. (1849) | Greene: Pittonia 5: 59. (1902) |
Web links |