Erigeron quercifolius |
Erigeron grandiflorus |
|
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oak-leaf fleabane |
large-flower daisy, large-flower fleabane, onestem fleabane, Rocky Mountain alpine fleabane |
|
Habit | Perennials, 2–25 cm; rhizomatous, fibrous-rooted, caudices or rhizomes crownlike or branches relatively short and thick. | |
Stems | erect to basally ascending (green proximally), proximally villous to villoso-hirsute, distally loosely strigose to hirsute, eglandular. |
erect to decumbent-ascending, sparsely to moderately pilose to villoso-hirsute, often stipitate-glandular over all or part. |
Leaves | basal (persistent) and cauline; basal blades oblanceolate to obovate or spatulate, 15–110(–150) × 4–25(–30) mm, margins serrate or crenate to pinnately lobed, faces hirsute to villous, eglandular; cauline blades becoming oblong, gradually reduced distally (reduced to bracts or 0 proximal to arrays, 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 | 2.5–4 × 4.5–10 mm. |
5–8(–10) × 8–20 mm. |
Ray florets | 100–150; corollas usually blue, sometimes white to pink, 4–6 mm, laminae not coiling or reflexing. |
50–130; corollas blue to pink or purplish, rarely white, 7–11(–15) mm (mostly 1–2 mm wide), laminae coiling. |
Disc corollas | 1.5–2.8 mm. |
2.4–4(–5) mm. |
Phyllaries | in (2–)3–4 series (sometimes basally connate), strigose to hirsuto-villous, eglandular or sparsely 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 | (1–)4–16(–50) in corymbiform arrays (from branches distal to midstem). |
1. |
Cypselae | 0.6–0.9 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 10–15 bristles. |
1.8–2.4 mm, 2-nerved, faces strigose; pappi: outer of setae, inner of (7–)10–18(–22) bristles. |
Winter | annuals, biennials, or short-lived perennials, 10–60 cm; fibrous-rooted, caudices simple. |
|
2n | = 18. |
= 18, 27. |
Erigeron quercifolius |
Erigeron grandiflorus |
|
Phenology | Flowering (Feb–)Mar–Jun. | Flowering Jul–Aug(–Sep). |
Habitat | Sandy sites, shell rock, roadsides, ditches, fields, areas of pine flatwoods | Rocky sites, meadows, alpine or near timberline |
Elevation | 0–15 m (0–0 ft) | 2900–4200 m (9500–13800 ft) |
Distribution |
FL; GA; NC; SC; VA; West Indies (Bahama Islands)
|
AZ; CO; ID; MT; NM; OR; UT; WY; AB; BC
|
Discussion | Erigeron quercifolius is primarily of the Atlantic coastal plain. Putative records from Alabama westward to Texas are based on specimens of E. philadelphicus or E. tenuis. Erigeron tenuis sometimes closely approaches E. quercifolius in overall appearance; it is more closely related to E. strigosus. Convergent plants of E. tenuis differ from E. quercifolius in their non-clasping cauline leaves, lanceolate (versus oblanceolate to obovate) phyllaries, and slightly longer cypselae (1–1.2 mm versus 0.6–0.9 mm). (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. 320. | FNA vol. 20, p. 324. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. simplex | |
Name authority | Lamarck: in J. Lamarck and J. Poiret, Tabl. Encycl. 3: 258. (1796) | Hooker: Fl. Bor.-Amer. 2: 18, plate 123. (1834) |
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