Erigeron filifolius |
Erigeron philadelphicus |
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threadleaf fleabane |
Philadelphia fleabane |
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Habit | Plants perennial, 9–40 cm; taprooted, with branching caudices. | Plants annual, biennial, or short-lived perennial, 10–80 cm; roots fibrous, caudices usually simple. |
Stems | erect, moderately to densely strigose, eglandular. |
erect, sparsely to moderately hirsute to lanate, minutely glandular. |
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. |
withering by flowering, oblanceolate to nearly spatulate, 20–170 × 5–35 mm; margins nearly entire, coarsely serrate, lobulate, or shallowly dentate; surfaces slightly to moderately strigose or hirsute, eglandular. |
Cauline leaves | gradually reduced distally or not. |
oblanceolate to lanceolate to elliptic or oblong, 5–130 × 3–25 mm, distally reduced, bases clasping; surfaces eglandular. |
Involucres | 4–6 × 7–11 mm. |
3–6 × 6–15 mm. |
Ray florets | 20–40, white to purple; rays 3–9 × 0.7–1.5 mm. |
150–250, white to pink; rays 2–7 × 0.2–0.5 mm. |
Disc florets | corollas 2–4 mm. |
corollas 2–3 mm. |
Phyllaries | in 2–4 series; surfaces moderately to densely strigose or villous, sometimes nearly glabrous distally, densely minutely glandular. |
in 2–3 series; surfaces sparsely to moderately hirsute, minutely glandular. |
Fruits | 1–3 mm, sparsely strigose; inner pappi of numerous barbellate bristles. |
1–1.5 mm, sparsely to moderately strigose; inner pappi of numerous barbellate bristles. |
Heads | 1–5 in corymb-like arrays, radiate. |
(1)3–many in corymb-like arrays, radiate. |
2n | =18. |
=18. |
Erigeron filifolius |
Erigeron philadelphicus |
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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. |
Disturbed areas, streambanks, fields, meadows, forest openings. Flowering Apr–Sep. 0–1900 m. All ecoregions. CA, ID, NV, WA; nearly worldwide. Native. |
Source | Flora of Oregon, volume 2, page 256 James Riser, Stephen Meyers |
Flora of Oregon, volume 2, page 260 James Riser, Stephen Meyers |
Sibling taxa | ||
Synonyms | Erigeron filifolius var. filifolius, Erigeron filifolius var. robustior | Erigeron philadelphicus var. philadelphicus |
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