Helenium amarum (Rafinesque) H. Rock. Bitterweed. Phen: May-Dec. Hab: Roadsides, overgrazed pastures, urban areas; in much of our area an introduction from farther west. Dist: Apparently native to e. and c. TX; now widespread in e. North America.

Origin/Endemic status: Native

Taxonomy Comments: Bierner (1989) discussed the taxonomy of section Amarum, consisting only of the two varieties of H. amarum.

Other Comments: The plant has a very bitter taste and is generally avoided by grazing animals, a point noted by Rafinesque in his original description (in 1817): "the whole plant is odoriferous and intensely bitter, it gives an abominable taste to the milk of the cows that feed on it in summer". Overgrazed areas come to be dominated by H. amarum. In areas where it is frequently mowed, H. amarum appears to evolve a genotype capable of flowering and fruiting when only a few cm tall.

Synonymy: = G, GrPl, Oh3, RAB, Tn, W, Bierner (1972); = Helenium amarum (Raf.) H.Rock var. amarum – Ar, C, FNA21, K1, K3, K4, NcTx, NE, NY, Pa, Va, WH3, Bierner (1989); = Helenium tenuifolium Nutt. – F, S; = n/a – Tat; < Helenium amarum (Raf.) H.Rock – Fl7, Il, Mi, SE1

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Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: FACU (taxonomic split from wetland indicator species)
• Eastern Mountains and Piedmont: FACU
• Great Plains: FACU (taxonomic split from wetland indicator species)
• Midwest: FACU (taxonomic split from wetland indicator species)
• Northcentral & Northeast: FACU (taxonomic split from wetland indicator species)

Heliophily: 9