Erigeron filifolius |
Erigeron disparipilus(synonym of Erigeron davisii) |
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threadleaf fleabane |
Snake River daisy, white cushion fleabane |
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Habit | Plants perennial, 9–40 cm; taprooted, with branching caudices. | Plants perennial, 8–22 cm; taprooted, with branching caudices. |
Stems | erect, moderately to densely strigose, eglandular. |
erect, sparsely to moderately hirsute to strigose, eglandular. |
Basal leaves | persistent, linear to filiform, 20–80 × 0.5–2 mm; margins entire; tips rounded to acute or acuminate; surfaces moderately to densely strigose. |
persistent, narrowly spatulate to narrowly oblanceolate-elliptic, 30–80 × 3–5 mm; margins entire, with 1 prominent vein; surfaces moderately to densely strigose, eglandular. |
Cauline leaves | gradually reduced distally or not. |
few, linear, 10–40 × 1–3 mm, reduced distally. |
Involucres | 4–6 × 7–11 mm. |
3.5–8 × 12–18 mm. |
Ray florets | 20–40, white to purple; rays 3–9 × 0.7–1.5 mm. |
25–50, white or cream, occasionally fading to pink; rays 4–8 × 1–3 mm. |
Disc florets | corollas 2–4 mm. |
corollas 3–4 mm. |
Phyllaries | in 2–4 series; surfaces moderately to densely strigose or villous, sometimes nearly glabrous distally, densely minutely glandular. |
in 2–3 series, usually with dark green medial area with or without orange stripe; surfaces moderately to densely hirsute or strigose, moderately to densely glandular. |
Fruits | 1–3 mm, sparsely strigose; inner pappi of numerous barbellate bristles. |
1.5–3 mm, sparsely to moderately strigose; inner pappi of numerous barbellate bristles. |
Heads | 1–5 in corymb-like arrays, radiate. |
usually 1, radiate. |
2n | =18. |
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Erigeron filifolius |
Erigeron disparipilus |
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Distribution | ||
Discussion | Rocky areas, sagebrush, juniper and pine forests. Flowering Apr–Aug. 50–2200 m. BR, BW, Col, ECas, Lava, Owy. CA, ID, NV, WA; north to British Columbia, northeast to MT, southeast to UT. Native. If subspecific taxa were recognized, Oregon specimens would correspond to the typical variety. |
Open rocky areas, ridges. Flowering Jun–Jul. 1100–1800 m. BW. ID, WA. Native. Some floras recognize plants with stem hairs in the same orientation (versus mixed) as E. davisii. The ranges and habitat of these taxa are, however, sympatric. Until further evidence shows otherwise, there is no compelling reason to recognize E. davisii as distinct from E. disparipilus. |
Source | Flora of Oregon, volume 2, page 256 James Riser, Stephen Meyers |
Flora of Oregon, volume 2, page 255 James Riser, Stephen Meyers |
Sibling taxa | ||
Synonyms | Erigeron filifolius var. filifolius, Erigeron filifolius var. robustior | Erigeron davisii, Erigeron engelmannii, Erigeron engelmannii ssp. davisii, Erigeron engelmannii var. davisii |
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