Erigeron tracyi

Greene

Pittonia 5: 59. 1902.

Common names: Running fleabane
Illustrated
Basionym: Erigeron cinereus A. Gray 1849
Synonyms: Erigeron colomexicanus A. Nelson Erigeron commixtus Greene Erigeron divergens var. cinereus A. Gray
Treatment appears in FNA Volume 20. Treatment on page 340. Mentioned on page 261, 262, 264, 341, 342.

Annuals, biennials, or short-lived perennials, 2.5–8 (–12, 18) cm; usually taprooted, sometimes fibrous-rooted, caudices simple or branched. Stems first erect (greenish proximally), then producing herbaceous, leafy, prostrate runners (stoloniform branches, sometimes with rooting plantlets at tips), densely hirsutulous (hairs spreading-deflexed, of relatively even lengths and orientations), sparsely minutely glandular. Leaves mostly basal (persistent in early season); blades oblanceolate to spatulate (obovate-elliptic laminae), 10–30 (–60) × 3–6 (–12) mm, cauline abruptly reduced distally, margins entire, dentate, or lobed, faces densely hirsute, eglandular. Heads 1 (–3 rarely, from midstem or proximal branches). Involucres 3.5–4.5 (–6) × 6–9 (–12) mm. Phyllaries in 3–4 series, sparsely to moderately hirsute, minutely glandular. Ray-florets 60–130; corollas white, often purplish abaxially, sometimes with an abaxial midstripe, 5–9 mm, laminae not coiling or reflexing. Disc corollas 2–3 mm (throats indurate and slightly inflated). Cypselae 0.7–1.3 mm, 2-nerved, faces sparsely strigose; pappi: outer of setae, inner of 12–16 bristles. 2n = 27.


Phenology: Flowering Mar–Oct.
Habitat: Desert scrub, grassy slopes, oak chaparral, pinyon-juniper woodlands, Douglas fir-ponderosa pine
Elevation: 700–2300(–2400) m

Distribution

V20-782-distribution-map.gif

Ariz., Colo., Kans., Nev., N.Mex., Okla., Tex., Utah, Mexico (Baja California), Mexico (Chihuahua), Mexico (Coahuila), Mexico (Durango), Mexico (Sonora), Mexico (Zacatecas)

Discussion

In March through June, plants of Erigeron tracyi produce leaves in a basal rosette usually with a single, erect, monocephalous, stem. Stoloniform branches are soon formed (often recognized on pressed specimens by the leaves mostly on one side of the branches), and by the end of the season (August through October), prostrate runners are usually evident, sometimes forming terminal, rooting plantlets.

Erigeron tracyi is similar in habit to E. flagellaris, particularly in the herbaceous stolons or stoloniform branches; the stem pubescence of E. tracyi is different, the stolons much less commonly produce rooting plantlets at the tips, and the plants tend to be perennial with woody or lignescent caudices, although they are variable both in habit and duration. Apparent hybrids with E. modestus and E. flagellaris are occasionally encountered, and the most common form of E. tracyi is perhaps (speculative) a stabilized, apomictic hybrid between the latter and E. divergens. All chromosome counts thus far have shown E. tracyi to be triploid and asynaptic.

Selected References

None.

Lower Taxa

None.
... more about "Erigeron tracyi"
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 +
Greene +
decurrent +
Erigeron cinereus +
3 cm30 mm <br />0.03 m <br /> (6 cm60 mm <br />0.06 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
1 cm10 mm <br />0.01 m <br /> (3 cm30 mm <br />0.03 m <br />) +
oblanceolate;spatulate +
3mm;6mm +
rugulose +  and muricate +
branched +  and simple +
Running fleabane +
not 2-lipped +  and actinomorphic +
purplish +  and white +
0.5 cm5 mm <br />0.005 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
beaked +, 2-ribbed +  and 5-ribbed +
subterete +, oblong +  and oblong-obovoid compressed +
fertile +  and bisexual +
0.2 cm2 mm <br />0.002 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
fertile +  and bisexual +
Ariz. +, Colo. +, Kans. +, Nev. +, N.Mex. +, Okla. +, Tex. +, Utah +, Mexico (Baja California) +, Mexico (Chihuahua) +, Mexico (Coahuila) +, Mexico (Durango) +, Mexico (Sonora) +  and Mexico (Zacatecas) +
700–2300(–2400) m +
strigose +  and hirsute +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Desert scrub, grassy slopes, oak chaparral, pinyon-juniper woodlands, Douglas fir-ponderosa pine +
disciform +  and discoid +
in loose , corymbiform or paniculiform arrays +  and singly +
indeterminate +
heterogamous +  and homogamous +
each +  and sessile +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
0.9 cm9 mm <br />0.009 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
turbinate;hemispheric +
0.6 cm6 mm <br />0.006 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
not coiling +
petiolate +  and sessile +
erect;spreading +
deltate +
lobed +  and dentate +
Not (?) +  and Scarious (?) +
2-carpellate +
Flowering Mar–Oct. +
3-nerved +  and 1-nerved +
narrowly elliptic +  and linear-lanceolate +
bearing subulate enations +, hairy +  and bristly +
exalbuminous +
Illustrated +
branched +  and simple +
prostrate +  and decumbent +
appendaged +  and truncate +
papillate +  and smooth +
Erigeron colomexicanus +, Erigeron commixtus +  and Erigeron divergens var. cinereus +
Erigeron tracyi +
Erigeron +
species +
inflated +  and tubular +
fibrous-rooted +  and taprooted +
90 cm900 mm <br />0.9 m <br /> (100 cm1,000 mm <br />1 m <br />) +
biennial +, perennial +, short-lived +  and annual +
18 (?) +, 2.5 (?) +  and 8 (?) +
2 cm20 mm <br />0.02 m <br /> (90 cm900 mm <br />0.9 m <br />) +
tree +, shrub +  and subshrub +