Erigeron compositus

Pursh

Fl. Amer. Sept. 2: 535. 1813.

Common names: Dwarf mountain fleabane vergerette à feuilles segmentées
Illustrated
Synonyms: Erigeron compositus var. discoideus A. Gray Erigeron compositus var. glabratus Macoun Erigeron compositus var. multifidus (Rydberg) J. F. Macbride & Payson Erigeron gormanii
Treatment appears in FNA Volume 20. Treatment on page 300. Mentioned on page 258, 260, 265, 301.

Perennials, 5–15 (–25 cm); taprooted, caudices simple or branches usually relatively thick and short, rarely slender and rhizomelike, covered with persistent leaf-bases. Stems erect (simple, ± scapiform), sparsely hispido-pilose, minutely glandular. Leaves mostly basal (persistent); blades spatulate to obovate-spatulate, 5–50 (–70) × (2–) 4–12 mm, margins (1–) 2–3 (–4) -ternately lobed or dissected, cauline bractlike, mostly entire, faces densely hispiduloso-puberulent to glabrate, minutely glandular. Heads (sometimes disciform) 1. Involucres 5–10 × 8–20 mm. Phyllaries in 2–3 series (purple-tipped), hirsute (hairs spreading), minutely glandular. Ray (pistillate) florets 20–60; corollas white to pink or blue, usually 6–12 mm, often reduced to tubes (heads disciform), laminae not coiling or reflexing. Disc corollas 3–5 mm. Cypselae 1.6–2.7 mm, 2-nerved, faces sparsely strigose-hirsute; pappi: outer usually of setae, sometimes 0, inner of 12–20 bristles. 2n = 18, 36, 45, 54.


Phenology: Flowering (May–)Jun–Aug.
Habitat: Sagebrush, rabbitbrush, aspen to aspen-fir, subalpine meadows, cliffs, talus, and boulders
Elevation: (in e Canada, possibly Greenland and Arctic bridge gap, 10–200–)1800–4300 m

Distribution

V20-642-distribution-map.gif

Greenland, Alta., B.C., Nfld. and Labr. (Nfld.), N.W.T., Nunavut, Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Mont., Nev., N.Dak., Oreg., S.Dak., Utah, Wash., Wyo., e Asia (Russian Far East)

Discussion

Correlations among ploidal level, breeding systems, and morphologic variation have been studied in detail in Erigeron compositus. Five informally designated population systems of diploids are geographically restricted (all of the northwestern United States and adjacent Canada) and primarily sexual, compared to the polyploids, which are agamospermous and apparently of hybrid origin, at least in some cases (R. D. Noyes et al. 1995; Noyes and D. E. Soltis 1996). Reduction in ray floret laminae usually is correlated with polyploidy. Plants with 1-ternately lobed leaves have been identified as var. glabratus, an element of variation that does not have a geographic pattern.

Among closely related species, Erigeron compositus is the only one that produces strongly thickened caudex branches; occasional collections show a tendency toward the slender, loose branches characteristic of the other species.

Lower Taxa

None.
... more about "Erigeron compositus"
54 +, 45 +, 36 +  and 18 +
not tailed +, rounded +  and obtuse +
distinct +
subequal +
scarious +
usually triangular +  and linear +
usually deltate +  and lanceolate +
paniculiform +, corymbiform +  and loose +
indeterminate +  and determinate +
Guy L. Nesom +
decurrent +
5 cm50 mm <br />0.05 m <br /> (7 cm70 mm <br />0.07 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (5 cm50 mm <br />0.05 m <br />) +
spatulate;obovate-spatulate +
4mm;12mm +
rugulose +  and muricate +
slender +
Dwarf mountain fleabane +  and vergerette à feuilles segmentées +
not 2-lipped +  and actinomorphic +
white +  and pink or blue +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
subterete +, oblong +  and oblong-obovoid compressed +
fertile +  and bisexual +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
fertile +  and bisexual +
Greenland +, Alta. +, B.C. +, Nfld. and Labr. (Nfld.) +, N.W.T. +, Nunavut +, Que. +, Sask. +, Yukon +, Alaska +, Ariz. +, Calif. +, Colo. +, Idaho +, Mont. +, Nev. +, N.Dak. +, Oreg. +, S.Dak. +, Utah +, Wash. +, Wyo. +  and e Asia (Russian Far East) +
(in e Canada, possibly Greenland and Arctic bridge gap, 10–200–)1800–4300 m +
strigose-hirsute +, densely hispiduloso-puberulent +  and glabrate +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Sagebrush, rabbitbrush, aspen to aspen-fir, subalpine meadows, cliffs, talus, and boulders +
disciform +  and discoid +
in loose , corymbiform or paniculiform arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
turbinate;hemispheric +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
not coiling +
petiolate +  and sessile +
erect;spreading +
deltate +
more or less dentate to pinnatifid +  and entire +
dissected +  and lobed +
Not (?) +  and Scarious (?) +
2-carpellate +
Flowering (May–)Jun–Aug. +
3-nerved +  and 1-nerved +
narrowly elliptic +  and linear-lanceolate +
Fl. Amer. Sept. +
bearing subulate enations +, hairy +  and bristly +
noyes1995a +  and noyes1996a +
exalbuminous +
Illustrated +
branched +  and simple +
prostrate +  and decumbent +
appendaged +  and truncate +
papillate +  and smooth +
Erigeron compositus var. discoideus +, Erigeron compositus var. glabratus +, Erigeron compositus var. multifidus +  and Erigeron gormanii +
Erigeron compositus +
Erigeron +
species +
inflated +  and tubular +
90 cm900 mm <br />0.9 m <br /> (100 cm1,000 mm <br />1 m <br />) +
2 cm20 mm <br />0.02 m <br /> (90 cm900 mm <br />0.9 m <br />) +
tree +, shrub +  and subshrub +