Erigeron grandiflorus |
Erigeron hessii |
|
---|---|---|
large-flower daisy, large-flower fleabane, onestem fleabane, Rocky Mountain alpine fleabane |
Hess' fleabane |
|
Habit | Perennials, 2–25 cm; rhizomatous, fibrous-rooted, caudices or rhizomes crownlike or branches relatively short and thick. | Perennials, 5–16 cm (often cespitose); rhizomatous, fibrous-rooted, thickened caudices or rhizomes branched, woody. |
Stems | erect to decumbent-ascending, sparsely to moderately pilose to villoso-hirsute, often stipitate-glandular over all or part. |
erect, loosely strigose to hirsute, eglandular. |
Leaves | basal (persistent) and cauline (petioles equaling or shorter than blades); blades oblanceolate to obovate or spatulate, 10–60(–90) × 3–8(–14) mm, cauline abruptly or gradually reduced distally, margins entire (apices rounded), faces sparsely hirsutulous or villous to sparsely strigose or glabrate, sometimes sparsely glandular. |
mostly basal (usually persistent); basal and proximal cauline blades oblanceolate to oblanceolate-spatulate, 20–50(–70) × 3–9 mm, distal bractlike (mid bases subclasping), margins entire with pair of teeth, faces glabrous or sparsely strigoso-hirsute, eglandular. |
Involucres | 5–8(–10) × 8–20 mm. |
5–6 × 8–13 mm. |
Ray florets | 50–130; corollas blue to pink or purplish, rarely white, 7–11(–15) mm (mostly 1–2 mm wide), laminae coiling. |
44–75; corollas white to lavender, 8–13 mm, laminae coiling slightly at tips. |
Disc corollas | 2.4–4(–5) mm. |
2.6–3.1 mm. |
Phyllaries | in 2–3 series (green or purplish), moderately to densely woolly-villous (hairs flattened, cross walls sometimes reddish), minutely glandular at least apically. |
in (2–)3–4 series (usually purplish), coarsely strigoso-hirsute along midribs, sparsely to densely minutely glandular (glands sometimes obscured by hairs). |
Heads | 1. |
1(–3). |
Cypselae | 1.8–2.4 mm, 2-nerved, faces strigose; pappi: outer of setae, inner of (7–)10–18(–22) bristles. |
1.1–1.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 13–18 bristles. |
2n | = 18, 27. |
|
Erigeron grandiflorus |
Erigeron hessii |
|
Phenology | Flowering Jul–Aug(–Sep). | Flowering May–Jun. |
Habitat | Rocky sites, meadows, alpine or near timberline | Andesitic dikes in otherwise rhyolitic rock, bedrock cracks in open areas, upper montane to subalpine conifer forests |
Elevation | 2900–4200 m (9500–13800 ft) | 2900–3100 m (9500–10200 ft) |
Distribution |
AZ; CO; ID; MT; NM; OR; UT; WY; AB; BC
|
NM |
Discussion | S. A. Spongberg (1971) recognized only the triploid populations as Erigeron grandiflorus and assigned the diploid ones to E. simplex. He hypothesized that the triploids incorporate genomic elements from an ancestor other than E. simplex. Based on his comments and annotations, however, triploids in southern Canada and the western United States apparently differ from the much more widespread diploids only quantitatively, having involucres and florets at the higher end of size ranges. Morphologic distinctions between the ploidal races do not provide a basis for consistent distinction. Spongberg (p. 200) also noted that “because of the intergrading of morphologic features of plants of Erigeron grandiflorus...the single most important criterion indicative of this taxon is highly irregular [in shape] and greatly abortive pollen.” These pollen features result from meiotic anomalies associated with the triploid condition. Specimen citations by A. Cronquist (1947) for Erigeron grandiflorus were mostly from collections of the species treated here as E. porsildii. He also cited two collections from southwestern Alberta; those and the type collection of E. grandiflorus (from the same region) are disjunct by more than 1500 kilometers from the more northern range of E. porsildii and instead lie at the northern extremity of the range of what previously has generally been identified as E. simplex. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Of conservation concern. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 324. | FNA vol. 20, p. 336. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. simplex | |
Name authority | Hooker: Fl. Bor.-Amer. 2: 18, plate 123. (1834) | G. L. Nesom: Brittonia 30: 440, figs. 1–5. (1978) |
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