Helenium thurberi

A. Gray

Proc. Amer. Acad. Arts 19: 32. 1883.

Common names: Thurber’s sneezeweed
Treatment appears in FNA Volume 21. Treatment on page 434. Mentioned on page 428, 432.
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Annuals, 40–100 cm. Stems usually 1, branched distally, moderately winged, sparsely hairy proximally, moderately hairy distally. Leaves glabrous or sparsely hairy (basal leaves withered by flowering); proximal blades lanceolate to lance-linear, usually irregularly laciniate; mid and distal blades lance-linear, entire. Heads 10–75 (–120+) per plant, in paniculiform arrays. Peduncles 3–10 cm, moderately hairy. Involucres ovoid to conic, 6–10 × 5–10 mm. Phyllaries (strongly connate proximally), moderately hairy. Ray-florets 0. Disc-florets 225–500+; corollas yellow-green proximally, brown to reddish-brown distally, 1–1.3 mm, lobes 4. Cypselae 0.9–1.2 (–1.5) mm, moderately hairy; pappi of 6 (–7) entire, non-aristate scales 0.2–0.5 mm. 2n = 26.


Phenology: Flowering (Mar–)May–Jul(–Sep).
Habitat: Ditches, around ponds, along streams, moist fields
Elevation: 30–1600 m

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Helenium thurberi"
not tailed +, rounded +  and obtuse +
connate +  and distinct +
subequal +
scarious +
usually ovate +  and lanceolate +
usually deltate +  and lanceolate +
paniculiform +
indeterminate +  and determinate +
Mark W. Bierner +
A. Gray +
decurrent +
compound +  and simple +
pinnatifid;lobed;spatulate;ovate;spatulate;ovate;oblong;oblanceolate;linear;lanceolate;elliptic +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Thurber’s sneezeweed +
brown +  and reddish-brown +
0.1 cm1 mm <br />0.001 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
4-5-angled +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
Ariz. +  and Mexico +
30–1600 m +
gland-dotted +
glabrous or +  and sparsely densely hairy +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Ditches, around ponds, along streams, moist fields +
discoid +  and radiate +
indeterminate +
homogamous +  and heterogamous +
each +  and sessile +
0.4 cm4 mm <br />0.004 m <br /> (3.4 cm34 mm <br />0.034 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (1 cm10 mm <br />0.01 m <br />) +
ovoid;conic +
0.5 cm5 mm <br />0.005 m <br /> (1 cm10 mm <br />0.01 m <br />) +
sessile +  and petiolate +
hairy +  and glabrous +
deltate +
dentate to pinnatifid or palmatifid +  and entire +
connate +  and distinct +
ovate +, oblong +, oblanceolate +, linear +, lanceolate +  and elliptic +
unequal +  and subequal +
2-carpellate +
persistent +
3 cm30 mm <br />0.03 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Flowering (Mar–)May–Jul(–Sep). +
9 +  and 34 +
laciniate +, lanceolate +  and lance-linear +
Proc. Amer. Acad. Arts +
neuter +  and pistillate +
bearing subulate enations +, hairy +  and bristly +
ovoid;hemispheric;ovoid;hemispheric;globose;conic +
non-aristate +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
exalbuminous +
winged +  and branched +
1 (?) +  and 10 (?) +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Compositae +
Helenium thurberi +
Helenium +
species +
urceolate +  and campanulate +
dilated +
toothed +  and entire +
40 cm400 mm <br />0.4 m <br /> (100 cm1,000 mm <br />1 m <br />) +
shrub +  and subshrub +