Senna pendula, also known as Easter Cassia, Christmas Senna, Winter Senna, Climbing Cassia, Golden Rain, Hanging Senna and valamuerto,
It's a shrubby plant of the Fabaceae family native to South America (source Wikipedia).
It's a wild plant with yellow flowers (although it can also be grown as an ornamental plant), these photographs were taken on a hillside in the city of Tampico Tamaulipas, Mexico. These flowers look beautiful.
