Ambrosia deltoidea, Triangle-leaf Bursage
Scientific Name: Ambrosia deltoidea
Common Name: Triangle-leaf Bursage
Also Called: Triangle Bur Ragweed, Triangle Bursage (Spanish: Chicurilla, Ambrosia, Estafiate, Chamizo Forrajero).
Family: Asteraceae, Sunflower Family
Synonyms: (Franseria deltoidea)
Size: About 2 feet or larger.
Growth Form: Shrub or subshrub; erect, gangly, somewhat rounded bush with slender brittle branches, new branches with tiny white hairs tomentose, reddish-brown, older branches grayish, dried or dead throughout.
Leaves: Greenish-gray above, grayish-white below; alternate, petiolate shape triangular, new leaves with very small whitish hairs tomentose about an inch long, margins toothed, drops leaves in extreme heat (drought-deciduous).
Flower Color: Greenish-yellow; dull, inconspicuous, flowers borne on a spike-type stalk (inflorescence) both male (staminate) and female (pistillate) flowers (monecious); (inflorescence), male flowers on top with the female flowers below, fruit is a rounded (globose) spiny bur, seed an achene.
Flowering Season: December to April.
Elevation: 1,000 to 3,000 feet.
Habitat Preferences: Rocky hillsides, plains, mesas and sandy washes.
Recorded Range: In the United States, Triangle-leaf Bursage is relatively rare where it is found only in Arizona. It is also native to Baja California and northwestern Mexico. In Arizona it grows in the central, southern and southwest parts of the state.
North America & US County Distribution Map for Ambrosia deltoidea.
U.S. Weed Information: No data available.
Invasive/Noxious Weed Information: No data available.
Wetland Indicator: No data available.
Threatened/Endangered Information: No data available.
Comments: Triangle-leaf Bursage is one of the most common plants in the lower Sonoran Desert. It is a dominate or co-dominant plant in desert scrub communities especially with Creosote Bush or Palo Verde or alone in a single stand. The type species was collected by Fremont on the Gila River, Arizona.
Triangle leaf Bursage is often used as a nurse plant by the Saguaro cactus. It is reported to have little or no value to livestock and normally lives about 50 years. As is the case for many members of this genus, pollen from the male flowers of Triangle-leaf Bursage causes hay fever in many people.
Also see in Southwest Desert Flora Canyon Ragweed, Ambrosia ambrosioides, White Bursage, Ambrosia dumosa, Hollyleaf Bursage, Ambrosia eriocentra, Burrobush, Ambrosia monogyra and Cheesebush, Ambrosia salsola.