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.
Koelreuteria bipinnata is commonly confused with this one. Look at the foliage, K. bipinnata are totally bipinnate while K. paniculata is only partially so.
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