Bur ragweed (Ambrosia confertiflora, Prodr. 5: 526 (1836))

Family: Asteraceae

Author: DC.

Bibliography: Prodr. 5: 526 (1836)

Year: 1836

Status: accepted

Rank: species

Genus: Ambrosia

Vegetable: Unknown

Observations: U.S.A. to Mexico

Description

Bur ragweed, scientifically known as Ambrosia confertiflora, belongs to the Asteraceae family, a diverse group renowned for its flowering species. This hardy perennial is indigenous to regions extending from the United States down to Mexico, thriving in varied terrains.

First introduced in the 1836 publication “Prodr. 5: 526” by the accomplished botanist DC, Ambrosia confertiflora stands out due to its adaptive nature and distinct physical features. Typically, bur ragweed exhibits a robust growth form, with a series of green, often hairy stems that bear a rough texture courtesy of small, bur-like projections. These projections are not merely for show but play a role in the plant’s reproduction and spread, facilitating its pervasion across landscapes through seed adherence to passing animals or human clothing.

The foliage of the bur ragweed is notable for its deeply lobed, pale green leaves, which, when crushed, release a scent that is typical of many species within the Asteraceae family. During its blooming period, Ambrosia confertiflora produces small, inconspicuous flowers clustered tightly together. These clusters, or inflorescences, contribute to the plant’s scientific epithet, “confertiflora,” which implies closely packed flowers.

In its natural habitat, the bur ragweed plays an essential role in the ecosystem. It provides cover and sometimes forage for local wildlife, while also competing aggressively with other plant species for resources. Its resilience and competitive nature, however, can sometimes pose challenges, especially in agricultural settings where it may become an unwelcome invader.

Understanding the ecological impact and management of bur ragweed is crucial, particularly for farmers and land managers in its native range throughout the United States and Mexico. As with many members of the Asteraceae family, Ambrosia confertiflora showcases the resilience, adaptability, and botanical intricacies that exemplify this large and complex family of flowering plants.

Common Names

Heb: ambrosia mecuneset
Eng: bur ragweed, ragweed, weakleaf bur ragweed, weakleaf burr ragweed, burr ragweed, slimleaf bursage
En: Bur ragweed, Weakleaf bur ragweed, Slimleaf bursage, Weakleaf burr ragweed, Ragweed, Burr ragweed
He: Ambrosia mecuneset, אמברוסיה מכונסת

Synonyms

• Gaertneria tenuifolia (Kuntze)
• Ambrosia caudata ((Rydb.) Shinners)
• Franseria tenuifolia var. tripinnatifida (A.Gray)
• Franseria hispidissima (Rydb.)
• Franseria strigulosa (Rydb.)
• Franseria confertiflora (Rydb.)
• Franseria caudata (Rydb.)
• Franseria pringlei (Rydb.)
• Franseria incana (Rydb.)

Distribution

• Arizona (native)
• California (native)
• Colorado (native)
• Dominican Republic (native)
• Kansas (native)
• Mexico Central (native)
• Mexico Gulf (native)
• Mexico Northeast (native)
• Mexico Northwest (native)
• Mexico Southwest (native)
• New Mexico (native)
• Oklahoma (native)
• Tennessee (native)
• Texas (native)
• Utah (native)
• Mexican Pacific Is. (introduced)
• New South Wales (introduced)
• Palestine (introduced)
• Queensland (introduced)
• South Australia (introduced)

Additional Images

Leaf

Taken Jul 18, 2021 by John Short (cc-by-sa)

Taken Jul 21, 2019 by CJL (cc-by-sa)

Flower

Taken Sep 29, 2021 by Shaeanna Downey (cc-by-sa)

Taken Oct 18, 2014 by EOL − Richard Spellenberg (cc-by-nc-sa)

Taken Oct 19, 2014 by EOL − Richard Spellenberg (cc-by-nc-sa)

Habit

Taken Nov 9, 2012 by EOL − Keir Morse (cc-by-nc-sa)

Taken Nov 9, 2012 by EOL − Keir Morse (cc-by-nc-sa)

Taken Nov 9, 2012 by EOL − Keir Morse (cc-by-nc-sa)

Taken Nov 9, 2012 by EOL − Keir Morse (cc-by-nc-sa)

Taken Jun 5, 2015 by EOL − snakeinmypocket (cc-by-nc)

© copyright of the Board of Trustees of the Royal Botanic Gardens, Kew.

Sources

• WFO (No URL)
• IPNI (No URL)
• GBIF (https://www.gbif.org/species/3110654)
• POWO (http://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:176072-1)
• PlantNet (https://identify.plantnet.org/species/the-plant-list/Ambrosia confertiflora DC.)

Specifications

Growth