Helenium amarum

Helenium amarum

Secure  (NatureServe)[1]
Scientific classification Edit this 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[2][3]
  • Gaillardia amara Raf.
  • Galardia amara Raf.
  • Helenium badium (A.Gray ex S.Watson) Greene

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)[4] and northern Mexico (Chihuahua, Coahuila),[5] and it is present elsewhere in North America, Australia, and the West Indies as an introduced species.[4][6][7][8]

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.[5]

The plant is somewhat toxic to mammals[9] and insects[10] due to the presence of the lactone tenulin.

Varieties[2][5]

References

  1. ^ "NatureServe Explorer 2.0". explorer.natureserve.org.
  2. ^ a b "Helenium amarum". The Plant List. Royal Botanic Gardens, Kew. Note that this website has been superseded by World Flora Online
  3. ^ "Gaillardia amara". Tropicos. Missouri Botanical Garden.
  4. ^ a b Kartesz, John T. (2014). "Helenium amarum". County-level distribution map from the North American Plant Atlas (NAPA). Biota of North America Program (BONAP).
  5. ^ a b c 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: Oxford University Press – via eFloras.org, Missouri Botanical Garden, St. Louis, MO & Harvard University Herbaria, Cambridge, MA.
  6. ^ Turner, B. L. 2013. The comps of Mexico. A systematic account of the family Asteraceae (chapter 11: tribe Helenieae). Phytologia Memoirs 16: 1–100.
  7. ^ Tropicos, specimen listing for Helenium amarum (Raf.) H. Rock
  8. ^ Queensland Government, Department of Agriculture and Fisheries, Bitter weed (Helenium amarum)
  9. ^ 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.
  10. ^ 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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