Helenium amarum

Helenium amarum is a species of annual herb in the daisy family known by the common names yellowdicks, yellow sneezeweed, fiveleaf sneezeweed, and bitter sneezeweed. It is native to much of the south-central United States (Texas, Oklahoma, Louisiana, Arkansas, New Mexico)[3] and northern Mexico (Chihuahua, Coahuila),[4] and it is present elsewhere in North America, Australia, and the West Indies as an introduced species.[3][5][6][7]

Helenium amarum
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Asterales
Family: Asteraceae
Genus: Helenium
Species:
H. amarum
Binomial name
Helenium amarum
(Raf.) H.Rock
Synonyms[1][2]
  • Gaillardia amara Raf.
  • Galardia amara Raf.
  • Helenium badium (A.Gray ex S.Watson) Greene

Helenium amarum is a multibranched bushy erect plant reaching 20 to 70 centimeters (8-28 inches) in height and thickly foliated in narrow to threadlike leaves. The tops of stem branches hold inflorescences of many daisy-like flower heads. Each head has a rounded center of sometimes as many as 250 golden yellow disc florets and a fringe of 8-10 usually lighter yellow ray florets which are reflexed away from the center. The fruit is a tiny achene about a millimeter long. This herb is weedy in some areas.[4]

The plant is somewhat toxic to mammals[8] and insects[9] due to the presence of the lactone tenulin.

Varieties[1][4]

References
  1. "Helenium amarum". The Plant List. Missouri Botanical Garden. Royal Botanic Gardens, Kew.{{cite web}}: CS1 maint: others (link)
  2. "Gaillardia amara". Tropicos. Missouri Botanical Garden.
  3. "Helenium amarum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP). 2014.
  4. Bierner, Mark W. (2006). "Helenium amarum". In Flora of North America Editorial Committee (ed.). Flora of North America North of Mexico (FNA). Vol. 21. New York and Oxford – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  5. Turner, B. L. 2013. The comps of Mexico. A systematic account of the family Asteraceae (chapter 11: tribe Helenieae). Phytologia Memoirs 16: 1–100.
  6. Tropicos, specimen listing for Helenium amarum (Raf.) H. Rock
  7. Queensland Government, Department of Agriculture and Fisheries, Bitter weed (Helenium amarum)
  8. Ivie, G. W., et al. (1975). Toxicity and milk bittering properties of tenulin, the major sesquiterpene lactone constituent of Helenium amarum (bitter sneezeweed). J Agric Food Chem 23:5 845-9.
  9. Arnason, J. T., et al. (1987). Mode of action of the sesquiterpene lactone, tenulin, from Helenium amarum against herbivorous insects. J Nat Prod 50:4 690-5.


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