Erigeron glabellus

Nuttall
Gen. N. Amer. Pl. 2: 147. 1818.
Common names: Streamside fleabane
Endemic
Treatment appears in FNA Volume 20. Treatment on page 331. Mentioned on page 259, 263, 267, 332.

Biennials or perennials, 7–50(–70) cm; rhizomatous, caudices or rhizomes relatively short and thickened, simple or branched, usually appearing merely fibrous-rooted. Stems erect or slightly basally ascending, hirsute or hirsuto-villous to strigose or glabrate, eglandular. Leaves basal (persistent) and cauline; basal blades oblanceolate to oblanceolate-spatulate, 40–150 × 3–15 mm, margins usually entire, sometimes shallowly dentate, faces hirsute or hirsuto-villous to sparsely strigose or glabrate, eglandular; cauline blades usually becoming lanceolate, abruptly or gradually reduced distally (bases sometimes subclasping). Heads 1–15. Involucres 5–9 × 10–20 mm. Phyllaries in (2–)3–4 series (greenish), hirsute to strigose, eglandular. Ray florets 125–175; corollas white to pink or blue, 8–15 mm, laminae (nearly filiform) coiling tardily at tips. Disc corollas 4–5.5 mm. Cypselae 1.2–1.5 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 16–20 bristles.

Distribution

V20-753-distribution-map.gif

Alta., B.C., Man., N.W.T., Ont., Sask., Yukon, Alaska, Colo., Idaho, Minn., Mont., N.Dak., N.Mex., S.Dak., Utah, Wis., Wyo.

Discussion

Varieties 2 (2 in the flora).

Erigeron glabellus is recognized by its subsimple caudices and fibrous-rooted bases, relatively numerous rays with nearly filiform laminae, and nonglandular vestiture.

Selected References

None.

Key

1 Stems strigose (hairs closely appressed to ascending), sometimes sparsely so to glabrate Erigeron glabellus var. glabellus
1 Stems hirsute to hirsuto-villous (hairs spreading) Erigeron glabellus var. pubescens