Trailing branches, coarsely dentate leaf margins, and 6 mericarps (listed as a rare variation from the usual 5) all lead me to A. parvulum. I'd like to revisit to confirm. On social trail in Rincon Creek area. Dry slope above drainage. Rincon Mountains, Saguaro National Park. http://swbiodiversity.org/seinet/taxa/index.php?taxauthid=1&taxon=3659&cl=3182