Definition

Noun: 1. A tall, coarse annual North American weed (Ambrosia trifida) of the aster family, having rough, hairy stems, leaves that are typically deeply three-lobed or five-lobed, and producing abundant pollen that is a major cause of hay fever. It is also known as giant ragweed.

Usage

• This term is used specifically in botany, ecology, agriculture, and medicine (particularly allergology) to identify this particular plant species.
• It is a common name, with "giant ragweed" being a frequent synonym.
• Example: "The field was overrun with great ragweed, which made my allergies terrible."

Examples

• "Farmers struggle to control great ragweed because it competes aggressively with crops."
• "The botanist identified the tall plant with lobed leaves as great ragweed."
• "During late summer, the pollen count for great ragweed is often very high."

Advanced Usage

• The species name is used in formal scientific contexts.
• The plant is often discussed in the context of invasive species management and public health due to its highly allergenic pollen.

Variants and Related Words

• Giant ragweed: The most common synonym.
• Ambrosia trifida: The formal botanical (Latin) name.
• Ragweed: The general term for plants in the genus, which includes common ragweed ().

Synonyms

• Giant ragweed
• Buffalo weed
• Horse cane

Notes

• "Great ragweed" is a compound noun. The word "great" in this context refers to the plant's large size compared to other ragweed species, not to a quality of excellence.
• It is a significant agricultural pest and a primary cause of seasonal allergic rhinitis (hay fever) in North America.

Noun

1. a coarse annual with some leaves deeply and palmately three-cleft or five-cleft