Helenium arizonicum

S. F. Blake

J. Wash. Acad. Sci. 27: 388. 1937.

Common names: Arizona sneezeweed
Treatment appears in FNA Volume 21. Treatment on page 432. Mentioned on page 428.
Revision as of 22:36, 29 July 2020 by imported>Volume Importer
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Annuals, 30–70 cm. Stems usually 1, sparingly branched distally, weakly winged, glabrous or sparsely hairy. Leaves glabrous or sparsely hairy; blades all lance-linear, entire or coarsely toothed. Heads 1–15 (–25) per plant, in paniculiform arrays. Peduncles 4–13 cm, glabrous or sparsely to moderately hairy. Involucres globoid to ovoid, 11–16 × 14–20 mm. Phyllaries sparsely to densely hairy. Ray-florets 12–18, pistillate, fertile; corollas usually yellow, sometimes yellow with purple streaks, 10–20 × 5–13 mm. Disc-florets 300–500 (–700+); corollas yellow proximally, yellow to purple to dark blue-purple distally, 3.2–3.6 mm, lobes 5. Cypselae 2–2.9 mm, moderately hairy; pappi of 6–7 entire, aristate scales 1.5–2 mm. 2n = 30.


Phenology: Flowering Jul–Sep.
Habitat: Pine forests, edges of wet places such as bogs, ponds, lakes, ditches
Elevation: 1800–2400 m

Discussion

Selected References

None.

Lower Taxa

None.
... more about "Helenium arizonicum"
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 +
S. F. Blake +
decurrent +
compound +  and simple +
toothed;entire;lance-linear +
winged;ribbed;winged;ribbed +
tuberculate +  and rugose +
barbellulate +  and barbellate +
Arizona sneezeweed +
purple;dark blue-purple +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
0.32 cm3.2 mm <br />0.0032 m <br /> (0.36 cm3.6 mm <br />0.0036 m <br />) +
0.5 cm5 mm <br />0.005 m <br /> (1.3 cm13 mm <br />0.013 m <br />) +
4-5-angled +  and obpyramidal +
fertile +  and bisexual +
fertile +  and bisexual +
1800–2400 m +
gland-dotted +
glabrous or +  and sparsely densely hairy +
pistillate +, staminate +  and neuter +
winged +  and beaked +
dispersed +
Pine forests, edges of wet places such as bogs, ponds, lakes, ditches +
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 />) +
1.1 cm11 mm <br />0.011 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
1.4 cm14 mm <br />0.014 m <br /> (2 cm20 mm <br />0.02 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 +
glabrous or +  and sparsely moderately hairy +
4 cm40 mm <br />0.04 m <br /> (13 cm130 mm <br />0.13 m <br />) +
Flowering Jul–Sep. +
9 +  and 34 +
J. Wash. Acad. Sci. +
bearing subulate enations +, hairy +  and bristly +
ovoid;hemispheric;ovoid;hemispheric;globose;conic +
6 +  and 7 +
aristate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
exalbuminous +
winged +  and branched +
1 (?) +  and 10 (?) +
hairy +  and glabrous +
appendaged +  and truncate +
hirsutulous +  and glabrous +
papillate +
Compositae +
Helenium arizonicum +
Helenium +
species +
urceolate +  and campanulate +
dilated +
toothed +  and entire +
30 cm300 mm <br />0.3 m <br /> (70 cm700 mm <br />0.7 m <br />) +
shrub +  and subshrub +