The golden raintree is a nice small to medium sized deciduous summer blooming tree. Related to the larger and more commonly planted K. bipinnata it shares some of the leaf and flower characteristics. However, its a much smaller tree growing to 30 feet. Usually forms a nicely rounded, fairly compact crown. Trees have the ability to produce decent yellowish fall color.
The deciduous leaves are alternately arranged, 8-14" long, pinnately compound. The leaflets have differing degrees of incised margins resulting in some leaflets looking/being compound. This would result in the leaf being considered bipinnate. Generally you will see the leaflets in the middle of the leaf more compound than others.
New foliage emerges red. Nice looking in the spring.
Stems are reasonably stout, brown with some distinct lenticels. Buds are small and pointed. Stems much smoother than K. bipinnata.
The small yellow flowers (1/2") are arranged in large panicles that develop at the ends of the current seasons growth. The common name arises when the flowers all fall to the ground creating yellow rain. Can say I have seen that heavy flowering.
Fruit is a capsule, red or orange when ripening and maturing a tan color with a small black seed inside, sort of like a chinese lantern.
Bark is pretty, brown with furrows that have an orangish color.
Misidentification
Koelreuteria bipinnata is commonly confused with this one. Look at the foliage, K. bipinnata are totally bipinnate while K. paniculata is only partially so.
Location
Aptos
Deluxe Foods Parking lot