Erigeron caespitosus |
Erigeron hyssopifolius |
|
---|---|---|
tuft daisy, tuft fleabane |
hyssop-leaf fleabane, vergerette à feuilles d'hysope |
|
Habit | Perennials, 5–25(–30) cm; taprooted, caudices relatively thick, usually branched. | Perennials, 5–35 cm; rhizomatous, fibrous-rooted, caudices sometimes branched. |
Stems | decumbent-ascending (greenish proximally), usually densely hirsute to hirtellous (hairs spreading to deflexed, gradually attenuate, basal cells erect), sometimes strigose (in Saskatchewan and Yukon), eglandular. |
erect, sparsely and loosely strigose to strigoso-villous, eglandular. |
Leaves | basal (persistent) and cauline; basal blades (1–)3-nerved, narrowly oblanceolate to spatulate, (10–)20–90(–120) × 2–15 mm, margins entire (apices rounded to obtuse), faces densely hirtellous, eglandular; cauline blades oblong-ovate to linear, ± reduced distally. |
basal and proximal cauline much reduced or present as scales; cauline blades linear to linear-oblong or oblong-lanceolate, 10–30 × 1–5 mm, largest at midstem, then relatively even-sized to peduncles, margins entire, sometimes prominently ciliate, faces glabrous or sparsely villous. |
Involucres | 4–7 × 9–18 mm. |
4–6 × 6–12 mm. |
Ray florets | 30–100; corollas white to bluish, 5–15 mm, laminae coiling. |
20–50; corollas white, less commonly pinkish, or aging pinkish, 4–8 mm, laminae not coiling or reflexing. |
Disc corollas | 3–4.4 mm. |
3–4.6 mm. |
Phyllaries | in 3–4 series, densely hirsuto-canescent to hirtellous (hairs spreading), moderately minutely glandular. |
in 2–3 series, loosely and sparsely strigose, eglandular. |
Heads | 1–4 (branches from distal 1/2 of stem). |
1(–5). |
Cypselae | 1.7–2.2 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae or scales, inner of 15–25 bristles. |
1.3–1.6 mm, 5–6-nerved, faces glabrous; pappi: outer of setae, inner of 25–35 bristles. |
2n | = 18, 36. |
= 18. |
Erigeron caespitosus |
Erigeron hyssopifolius |
|
Phenology | Flowering Jun–Aug. | Flowering Jun–Aug. |
Habitat | Rocky or sandy, grassy hills, sagebrush-aspen, pinyon-juniper, to spruce and tundra northward | Open woods, river gravel, rock ledges and crevices, gravel barrens, roadsides |
Elevation | 1300–3000(–3600) m (4300–9800(–11800) ft) | 0–500 m (0–1600 ft) |
Distribution |
AK; AZ; CO; ID; MT; ND; NE; NM; SD; UT; WA; WY; AB; BC; MB; SK; YT
|
ME; MI; NH; NY; VT; AB; MB; NB; NF; NS; NT; NU; ON; QC; SK; YT
|
Discussion | Erigeron caespitosus as recognized here is highly variable and perhaps justifiably could be divided into more than one taxon. Plants at lower elevations tend to produce tall stems branching above the middle and long, white rays. At higher elevations, especially in Idaho, western Montana, Utah, and Wyoming, stems tend to be shorter and simple and the rays commonly are blue to violet. In the Bitterroot Mountains (Ravalli and Deerlodge counties, Montana), short-stemmed, blue-rayed plants also have strigose cauline vestiture (in contrast to typically deflexed-hirtellous stems); these vestiture variants occur in the same area with plants apparently similar in all other features. Strigose populational variants also occur in Saskatchewan and Yukon, and E. abajoensis, largely distinguished by strigose cauline vestiture, might be considered a regional variant of E. caespitosus. In eastern Idaho and southwestern Montana, plants of E. caespitosus are commonly encountered with cauline leaves obovate and distinctly subclasping. Plants with strongly 3-nerved basal leaves occur in Carbon and Gallatin counties, Montana. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Variety villicaulis, from Anticosti Island (Quebec) and Newfoundland, has been distinguished on the basis of its relatively shorter stature (mostly 3–15 cm) and greater ratio of peduncle to leafy-stem lengths (stems and peduncles as long as or longer than the leafy parts of stems); the distinction appears to be arbitrary. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 20, p. 283. | FNA vol. 20, p. 277. |
Parent taxa | Asteraceae > tribe Astereae > Erigeron | Asteraceae > tribe Astereae > Erigeron |
Sibling taxa | ||
Synonyms | E. hyssopifolius var. anticostensis, E. hyssopifolius var. villicaulis | |
Name authority | Nuttall: Trans. Amer. Philos. Soc., n. s. 7: 307. (1840) | Michaux: Fl. Bor.-Amer. 2: 123. (1803) |
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