SafePlants

Annual Ragweed (Ambrosia artemisiifolia)

Considerations for Pets

• The plant is described as hairy, which might cause mild irritation if ingested or contacted.
• It can be found in pastures, which may be accessible to some pets.

Considerations for Children

• The plant is described as hairy, which might cause mild irritation if touched.

Common Names

• Annual Ragweed
• Ambrosia
• Horseweed
• Asthma Plant
• Fever Weed
• Bitterweed
• Wild Tansy
• Blackweed
• Roman Wormwood
• Hogweed
• Carrotweed

Taxonomy and Nomenclature

• Scientific Name: Ambrosia artemisiifolia L.
• Family: Asteraceae (also known as the composite or daisy family)
• Synonyms:
  • Ambrosia artemisiifolia var. elatior
  • Ambrosia artemisiifolia var. paniculata
  • Ambrosia elatior

Distribution and Habitat

• Native to North America, particularly the eastern and north-central states.
• Introduced in various regions, including Australia and Europe.
• Commonly found in disturbed sites, roadsides, wastelands, and poor or overgrazed pastures.

Ecological Role

• Considered a significant weed in many agricultural settings, especially corn and soybean fields.
• Recognized as an invasive plant in Europe and other regions.
• Can be suppressed by winter annuals and perennial plants that out-compete it.

Morphological Characteristics

• Erect annual herb, typically growing to 0.5-2 meters tall, but can reach up to 3.5 meters.
• Much-branched along a somewhat hairy stem.
• Shallow, fibrous root system.
• Leaves are grey-green, hairy, and variable in shape.
• Lower leaves are ovate to lanceolate in outline, with blades up to 16 cm long.

Quirky Facts

• Annual Ragweed is considered a major cause of summertime hay fever allergies.
• The name "Annual Ragweed" comes from its annual growth cycle and the ragged appearance of its leaves.

Interactions with Other Organisms

• Its pollen is a common allergen.