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.

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 +