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.