This plant is growing in the desert in back of my home in Tucson Az. It has rounded green leaves unlike the ridged ones on Esperanza's. Yellow trumpet flower. It only lives on rain water. Can anyone tell me what this might be?
That's tree tobacco, Nicotiana glauca.
Native to South America and widely naturalized in warmer parts of the US. You'll find plenty more info and pics through a google search. Most people consider it a weed, and it is toxic, but it can be beautiful, in a scraggly sort of way!