Erigeron formosissimus

Perennials, 10–40(–55) cm; rhizomatous, fibrous-rooted, rhizomes variably thick. Stems ascending, densely hirsute to hirsutulous or glabrous, minutely glandular to stipitate-glandular. Leaves basal (persistent) and cauline; basal blades oblanceolate to oblanceolate-spatulate, 20–100(–150) × 4–10(–15) mm, margins entire, closely ciliate, faces glabrous or sparsely hirsute, sometimes sparsely glandular; cauline blades becoming ovate to lanceolate, gradually reduced distally (bases clasping). Heads 1–6. Involucres 5–8 × 10–20 mm. Phyllaries in 2–3 series (greenish), glabrous or hirsuto-villous, densely minutely glandular to stipitate-glandular (glands sometimes obscured by hairs in var. formosissimus). Ray florets 75–150; corollas blue to purple, rarely pink to white, 8–15 mm (ca. 1 mm wide), laminae coiling at tips or not at all. Disc corollas 3.5–4.5 mm. Cypselae (1.3–)1.6–1.9 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 15–25 bristles.

Distribution

• Generated Map
• Legacy Map

w United States.

Discussion

Varieties 2 (2 in the flora).

Variation in vestiture of Erigeron formosissimus is complex, ranging from stems and heads glabrous and densely stipitate-glandular to stems and heads densely hairy and essentially eglandular; intermediates are found over the range of the species. The taxonomic solution of recognizing broadly sympatric varieties within a single species is biologically untenable, and some have treated this as a single entity; the variation is greater than typically occurs within a single species of Erigeron (see comments following 3. E. neomexicanus, where the situation with E. oreophilus is similar).

Selected References

None.

Lower Taxa

Erigeron formosissimus var. formosissimus, Erigeron formosissimus var. viscidus

Key

1	Involucres moderately to densely hirsute, minutely glandular; distal leaves hirsuto-villous, eglandular or sometimes sparsely glandular	Erigeron formosissimus var. formosissimus
1	Involucres glabrous or sparsely hirsuto-villous, densely minutely glandular; distal leaves usually glabrous, sometimes sparsely villoso-hirsute, minutely glandular	Erigeron formosissimus var. viscidus