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Erigeron oreganus

Gorge daisy, gorge fleabane, Oregon fleabane

Snake River daisy, white cushion fleabane

Habit Plants perennial, 5–15 cm; taprooted, caudices unbranched. Plants perennial, 8–22 cm; taprooted, with branching caudices.
Stems

decumbent to erect; hirsute with unequal hairs, sparsely glandular.

erect, sparsely to moderately hirsute to strigose, eglandular.

Basal leaves

persistent, obovate, 15–90 × 5–20 mm;

margins coarsely serrate to shallowly lobulate;

surfaces sparsely to moderately hirsute to 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

obovate to elliptic; little or not reduced distally;

surfaces sparsely to moderately hirsute.

few, linear, 10–40 × 1–3 mm, reduced distally.

Involucres

4–7 × 9–15 mm.

3.5–8 × 12–18 mm.

Ray florets

30–60, pink to purple;

rays 4–5 × 0.5–1 mm.

25–50, white or cream, occasionally fading to pink;

rays 4–8 × 1–3 mm.

Disc florets

corollas 3–5 mm.

corollas 3–4 mm.

Phyllaries

in 2–3 series, pale green with dark green medial stripe;

surfaces remotely hirsute, strongly stipitate-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

2–3 mm, moderately strigose;

inner pappi of several unbarbed to weakly barbellate twisted bristles.

1.5–3 mm, sparsely to moderately strigose;

inner pappi of numerous barbellate bristles.

Heads

1–4, radiate.

usually 1, radiate.

Erigeron oreganus

Erigeron disparipilus

Distribution
[WildflowerSearch map]
[BONAP county map]
Discussion

Shady cliffs, rocky slopes, crevices. Flowering May–Aug. 100–400 m. Casc. WA. Native.

This uncommon species is found only in the Columbia River Gorge.

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 259
James Riser, Stephen Meyers
Flora of Oregon, volume 2, page 255
James Riser, Stephen Meyers
Sibling taxa
E. acris, E. aliceae, E. annuus, E. aphanactis, E. aureus, E. bloomeri, E. cascadensis, E. cervinus, E. chrysopsidis, E. compositus, E. corymbosus, E. coulteri, E. decumbens, E. disparipilus, E. divergens, E. eatonii, E. elegantulus, E. filifolius, E. foliosus, E. glacialis, E. glaucus, E. howellii, E. inornatus, E. karvinskianus, E. klamathensis, E. latus, E. linearis, E. lonchophyllus, E. nivalis, E. peregrinus, E. petrophilus, E. philadelphicus, E. poliospermus, E. pumilus, E. simplex, E. speciosus, E. stanselliae, E. strigosus, E. tener, E. vagus
E. acris, E. aliceae, E. annuus, E. aphanactis, E. aureus, E. bloomeri, E. cascadensis, E. cervinus, E. chrysopsidis, E. compositus, E. corymbosus, E. coulteri, E. decumbens, E. disparipilus, E. divergens, E. eatonii, E. elegantulus, E. filifolius, E. foliosus, E. glacialis, E. glaucus, E. howellii, E. inornatus, E. karvinskianus, E. klamathensis, E. latus, E. linearis, E. lonchophyllus, E. nivalis, E. oreganus, E. peregrinus, E. petrophilus, E. philadelphicus, E. poliospermus, E. pumilus, E. simplex, E. speciosus, E. stanselliae, E. strigosus, E. tener, E. vagus
Synonyms Erigeron davisii, Erigeron engelmannii, Erigeron engelmannii ssp. davisii, Erigeron engelmannii var. davisii
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