Ambrosia cordifolia

{{Short description|Species of flowering plant}}

{{Speciesbox

|image = Tucson bur ragweed imported from iNaturalist photo 366401606 on 10 September 2024.jpg

|genus = Ambrosia

|species = cordifolia

|authority = (A. Gray) W.W. Payne

|synonyms_ref = [http://www.tropicos.org/Name/2709268 Tropicos, Ambrosia cordifolia (A. Gray) W.W. Payne ][http://www.theplantlist.org/tpl1.1/record/gcc-5166 The Plant List Ambrosia cordifolia (A.Gray) W.W.Payne ]

|synonyms ={{Specieslist

|Franseria cordifolia|A.Gray

|Franseria malvacea|Rydb.

|Gaertnera cordifolia|(A.Gray) Kuntze

|Gaertneria cordifolia|(A.Gray) Kuntze

}}

}}

Ambrosia cordifolia, called the Tucson bur ragweed,[http://www.fireflyforest.com/flowers/76/ambrosia-cordifolia-tucson-bur-ragweed/ Southeastern Arizona Wildflowers and Plants, Ambrosia cordifolia – Tucson Bur Ragweed] is a North American species of plant in the family Asteraceae. It is native to northern Mexico (Sonora, Sinaloa, San Luis Potosí, Guanajuato, Baja California Sur) and the State of Arizona in the United States.[http://bonap.net/MapGallery/County/Ambrosia%20cordifolia.png Biota of North America Program 2014 county distribution map][http://www.tropicos.org/Name/2709268?tab=specimens Tropicos, specimen listing for Ambrosia cordifolia (A. Gray) W.W. Payne][https://www.biodiversitylibrary.org/page/8442724#page/424/mode/1up Payne, Willard William 1964. Journal of the Arnold Arboretum 45(4): 421]

Ambrosia cordifolia is a shrub up to 50 cm (20 inches) tall. Leaves are triangular or heart-shaped. Flower heads are small and inconspicuous, as the plant is wind-pollinated. The heads develop into spiny burs as the seeds ripen.[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=250066048 Flora of North America, Vol. 21 Page 14 Ambrosia cordifolia (A. Gray) W. W. Payne]

The reference to the Arizona city of Tucson in the common name refers to the species' first discovery by Cyrus G. Pringle in the mountains near Tucson in 1884.[https://www.biodiversitylibrary.org/page/38116778#page/455/mode/1up Gray, Asa 1884. Synoptical Flora of North America 1(2): 445] as Franseria cordifolia