A subshrub or shrub growing up to 2.5 m (2-7’)  tall with multiple erect stems and leaves covered with minute soft hairs containing glandular hairs that produce an aromatic sticky sap (1, 2). Leaves are dark grey-green, alternately arranged, 5-20mm (usually 8 inches) long, and lanceolate to triangular in shape with coarsely toothed margins (1, 2). Plants are dioceious with inconspicuous male flowers on an unbranched raceme and female flowers occurring proximal to the male flowers appearing in early to late spring (2). Fruit is a small, 10-15mm, ellipsoid/ fusiform burr with spines and hooks (1,2).

The genus Ambrosia was first named by Carl Linaeas, and is from the Greek word “food of the gods” (2).  Canyon ragweed occurs in coastal scrub and disturbed sites at elevations between 150-1200m in Arizona and northwestern Mexico (1,2). The plant is most often found in central, southern and western parts of Arizona (1,2).

Canyon ragweed grows in USDA Hardiness Zone 9a-11 where it prefers full sun and between 10 and 19” of precipitation annually (3).

Canyon ragweed attracts pollinators such as butterflies, bees and other small insects, and it may be eaten by birds and small mammals (2). The plant is also used medicinally as an analgesic for respiratory problems (2). A decoction from crushed roots was used to treat menstrual hemorrhage and pain while a poultice of warmed leaves was used to relieve chest congestion (2). Decoction of crushed roots taken by women for pains and menstrual hemorrhage (2).