Common Name: Bladder-senna
Colutea arborescens is a deciduous shrub. It sports pea-like yellow-orange flowers which turn into inflated seed-pods. There is a large specimen at the top of Black Garden as it slopes down to the Laburnum Walk. It looks very similar to C. x media in the same bed.
Flower photo by AnRo0002 - wikimedia.org
Bladder photo by Agnieszka Kwiecień - wikimedia.org
Shrub with bladders by Stefan.lefnaer - wikimedia.org