Erigeron speciosus |
Erigeron grandiflorus |
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aspen fleabane, showy daisy, showy fleabane, splendid fleabane |
large-flower daisy, large-flower fleabane, onestem fleabane, Rocky Mountain alpine fleabane |
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Habit | Perennials, 30–80(–100) cm; rhizomatous, fibrous-rooted, caudices relatively thick. | Perennials, 2–25 cm; rhizomatous, fibrous-rooted, caudices or rhizomes crownlike or branches relatively short and thick. |
Stems | erect, glabrous or sparsely hirsuto-pilose (hairs 0.5–1 mm), often minutely glandular distally. |
erect to decumbent-ascending, sparsely to moderately pilose to villoso-hirsute, often stipitate-glandular over all or part. |
Leaves | basal (usually withering by flowering) and cauline; basal blades oblanceolate-spatulate, 30–80(–150) × 4–18(–28) mm, margins entire, often ciliate (main veins sometimes also), faces glabrous, eglandular or distal sparsely minutely glandular; cauline blades ovate to ovate-lanceolate, oblong-lanceolate, or lanceolate, nearly even-sized distally or sometimes mid largest (continuing to immediately below heads, bases usually clasping to subclasping). |
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. |
Involucres | 6–9 × 11–22 mm. |
5–8(–10) × 8–20 mm. |
Ray florets | 75–150; corollas blue to lavender, rarely whitish, 8–16 mm (mostly 1 mm wide), laminae slightly coiling at least at tips. |
50–130; corollas blue to pink or purplish, rarely white, 7–11(–15) mm (mostly 1–2 mm wide), laminae coiling. |
Disc corollas | 4–5 mm. |
2.4–4(–5) mm. |
Phyllaries | in 2–3(–4) series, usually glabrous, sometimes sparsely hirsuto-pilose, minutely glandular. |
in 2–3 series (green or purplish), moderately to densely woolly-villous (hairs flattened, cross walls sometimes reddish), minutely glandular at least apically. |
Heads | (2–)4–20 in corymbiform arrays. |
1. |
Cypselae | 1.5–1.8 mm, 2(–4)-nerved, faces sparsely strigose; pappi: outer of setae, inner of 20–30 bristles. |
1.8–2.4 mm, 2-nerved, faces strigose; pappi: outer of setae, inner of (7–)10–18(–22) bristles. |
2n | = 18, 27. |
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Erigeron speciosus |
Erigeron grandiflorus |
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Phenology | Flowering Jul–Oct. | Flowering Jul–Aug(–Sep). |
Habitat | Dry or moist, gravelly or loamy soil, prairies, yellow pine, pine-fir, spruce-fir, aspen-spruce | Rocky sites, meadows, alpine or near timberline |
Elevation | (600–)900–3400 m ((2000–)3000–11200 ft) | 2900–4200 m (9500–13800 ft) |
Distribution |
AZ; CO; ID; MT; NM; NV; OR; SD; UT; WA; WY; AB; BC; Mexico (Baja California)
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AZ; CO; ID; MT; NM; OR; UT; WY; AB; BC
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Discussion | The population in Baja California is disjunct from the closest range in Arizona and northern Nevada. Plants glabrous and glandular on the phyllaries, stems, and leaves have been recognized as var. macranthus; they intergrade with hairier forms and do not show a coherent geographic pattern. Plants commonly identified as Erigeron subtrinervis var. conspicuus usually have stems sparsely hirsuto-pilose with hairs 1–1.5 mm, and the leaves commonly are ciliate on the margins and veins. As implied in the nomenclatural combination by Breitung, those plants are more similar to E. speciosus than to E. subtrinervis, and they apparently show part of the greater variability of E. speciosus in the northwestern part of its range (Alberta, British Columbia, Idaho, Montana, Oregon, Washington, and Wyoming), where more typical plants also occur. Erigeron speciosus and E. subtrinervis are sympatric over large parts of their ranges and appear to be at least partially reproductively isolated entities, although intermediates are frequently encountered. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 20, p. 330. | FNA vol. 20, p. 324. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | Stenactis speciosa, E. conspicuus, E. macranthus, E. speciosus var. conspicuus, E. speciosus var. macranthus, E. subtrinervis subsp. conspicuus, E. subtrinervis var. conspicuus | E. simplex |
Name authority | (Lindley) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 5: 284. (1836) | Hooker: Fl. Bor.-Amer. 2: 18, plate 123. (1834) |
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