big ol' bush
Bush growing in the dry bottom of Cottonwood Creek. I think the things in the last photo are old galls (there's one in the first photo as well).
Ragweeds are flowering plants in the genus Ambrosia in the aster family, Asteraceae. They are distributed in the tropical and subtropical regions of the New World, especially North America, where the origin and center of diversity of the genus are in the southwestern United States and northwestern Mexico. Several species have been introduced to the Old World and some have naturalized.