Helenium amarum (Rafinesque) H. Rock. Common name: Bitterweed. Phenology: May-Dec. Habitat: Roadsides, overgrazed pastures, urban areas; in much of our area an introduction from farther west. Distribution: 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, 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; Gaillardia amara Rafinesque. Basionym: Gaillardia amara Raf. 1817
Links to other floras: = Helenium amarum var. amarum - FNA21
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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
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© Bruce A. Sorrie | Original Image ⭷
© Sonnia Hill | Original Image ⭷
© Bruce A. Sorrie | Original Image ⭷
© Joey Shaw source | Original Image ⭷
© Scott Ward | Original Image ⭷
© Joey Shaw source | Original Image ⭷
© Scott Ward | Original Image ⭷
© Joey Shaw source | Original Image ⭷
© Aidan Campos source | Original Image ⭷Feedback
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Horticultural Information
Intro: Erect annual from a taproot, found in overgrazed pastures, roadsides and urban areas; apparently introduced from farther west.
Stems: Stems branched above, leafy, green to red-tinged, smooth.
Leaves: Leaves alternate, linear to nearly thread-like, to 3 in. long (not reduced upward), often with clusters of smaller leaves in leaf axils, gland-dotted and smooth.
Inforescence:
Flowers: Composite flowers (heads) at tips of branches; about 3/4 in. wide; consisting of 5-10 spreading to drooping, yellow, 3-toothed ray florets encircling a dome-shaped central disk composed of tiny, yellow tubular florets. Several green, drooping, pointed bracts surround the base of each head.
Fruits:
Comments: Foliage very bitter-tasting and in large quantities, toxic to horses and cows.
Height: 1-2 ft.
plant sale text:
bloom table text:
description: Erect annual from a taproot, found in overgrazed pastures, roadsides and urban areas; apparently introduced from farther west.
stems: Stems branched above, leafy, green to red-tinged, smooth.
leaves: Leaves alternate, linear to nearly thread-like, to 3 in. long (not reduced upward), often with clusters of smaller leaves in leaf axils, gland-dotted and smooth.
inflorescence:
flowers: Composite flowers (heads) at tips of branches; about 3/4 in. wide; consisting of 5-10 spreading to drooping, yellow, 3-toothed ray florets encircling a dome-shaped central disk composed of tiny, yellow tubular florets. Several green, drooping, pointed bracts surround the base of each head.
fruits:
comments: Foliage very bitter-tasting and in large quantities, toxic to horses and cows.
cultural notes:
germination code:
native range:
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