Ambrosia arborescens Mill.

Franseria arborescens Brand. Zoe 5: 162. 1903
Franseria carduacea Greena, Leaflets 2: 156. 1911.
A shrub or small tree, 3-5 m. high, canescent-pubescent; leaves alternate; petioles 2-3 cm. long; blades thick, up to 15 cm. Ion:;, 5-S cm. wide, ovate in outline, long-acuminate, deeply pinnately cleft, with 3-7 coarsely serrate lobes, pubes' mt beneath, greener and puberulcnt or hispidulous above; heads paniculate, the staminate ones above the pistillate ones; involucre rotate, 5-6 mm. broad, rather deeply cleft; lobes 9-12, lanceolate; paleae of the receptacle subulate, pubescent; corolla pubescent; style rather thick, fully as long as the stamens; stigma peltate, penicillate; pistillate heads 2-3-flowered; fruit pubescent, ellipticfusiform, 8-9 mm. long; beaks 2, more or less united below, elongate-conic, slightly hooked; spines 7-10, in about 3 series, subulate, pubescent, hooked at the apex.
Type LOCALITY: [Given as] "from Santa Gertrudis to Cabo San Lucas," but the type was collected at Ascension, Lower California. Distribution: Lower California.

Ambrosia arborescens is a species of plant in the family Asteraceae. It is native to the Andes from Colombia south to Bolivia.

In its native range, A. arborescens is used as a medicinal plant with analgesic, antiinflammatory and antiseptic properties.