Bitter sneezeweed, Basin sneezeweed
Helenium amarum (Raf.) H. Rock var. amarum
Asteraceae (Sunflower Family)
Description
Bitter sneezeweed and basin sneezeweed are erect, upper-branching native annuals that reach 10 to 20 inches tall. The entire plant of both varieties has a strong odor and is bitter to the taste.
The leaves are narrow and located alternately on the stem. In some years, the lower leaves are lost, new growth occurs up the stalk, and new flowers may appear in the fall.
A member of the Sunflower family, the plant has showy flowers that are noticeable in the late spring or summer and are located at the end of each branch. Two varieties of this plant are identical except for the flower color: one is all yellow, the other is yellow with a red-brown center. Each bloom has about eight cleft ray flowers (petals) with three lobes, often bending downward at maturity.
The plant is toxic to grazing livestock but is rarely consumed in toxic amounts.
Habitat
The yellow variety is widespread in disturbed, sandy or loamy soil in the eastern to central part of the state; the dark-centered variety is often found in calcareous soil in more central and western areas of the state.
Toxic Agent
A sesquiterpene lactone is responsible for the toxicity of bitter sneezeweed, which is greatest at time of lowering. This bitter plant is seldom consumed at a level high enough to produce clinical signs. However, it has been responsible for bitter, undrinkable milk and is suspected to be the cause of unpalatable meat from calves slaughtered off the range. The toxin is stable in plants contaminating hay.
Signs of Livestock Ingestion
Signs of bitter sneezeweed poisoning include: Weakness; Incoordination; Vomiting; Salivation; Diarrhea; Grinding of teeth.
Management Strategies
Avoid cutting hay containing a large amount of bitter sneezeweed. Do not feed hay containing any of the plant to lactating dairy cows. Do not slaughter grass-fed cattle from a pasture that contains bitter sneezeweed.
Severe infestations may be controlled with broadleaf herbicides such as 2,4-D or Grazon P+D® at 0.5 to 1.0 pound a.i./acre in the spring with good growing conditions.
Images
Plant Characteristics
Flower Color: Yellow
Seed Type: Non-Encapsulated
Duration: Annual
Stem Texture: Hairy
Growth Habit: Forbs/Broadleaf
Leaf Shape
: Simple with Pinnate or Parallel Venation
Season: Warm
Distribution
: 01 - Pineywoods, 02 - Gulf Prairies and Marshes, 03 - Post Oak Savannah, 04 - Blackland Prairies, 05 - Cross Timbers and Prairies, 06 - South Texas Plains, 07 - Edwards Plateau, 08 - Rolling Plains, 09 - High Plains, 10 - Trans-Pecos
Distributions
Distribution refers to the ecological region in Texas that a plant has been found. You can also view a clickable map.
Book: Brush and Weeds of Texas Rangelands (B-6208), Toxic Plants of Texas (B-6105)
Collection: Brush and Weeds, Toxics, Wild Flowers
Livestock Affected: Cattle
Livestock Signs: Depression/ Weakness, Diarrhea, Excess Salivation, Incoordination, Vomiting/Regurgitation
