Colutea x media
Common name: Bladder senna
Colutea x media: This deciduous shrub in the pea family has small orange-yellow flowers but is better known for its bladder seed-pods in mid-summer. It can be found at the top of the hillside facing the north end of the Laburnum Walk, along with its close relative, C. arborescens.
Flower photo by By 阿橋 HQ - wikimedia.org