What tree is the flower of that tree on Nanshan Road in Xiamen?

Small evergreen trees, up to 4-7 meters high. The leaves are big, heart-shaped and the stems are long. Flowers yellow, corolla bell-shaped, capsule.

In rural Taiwan Province, its leaves are often used to wrap Zong Bing, so it is also called a tall tree. Mainly distributed in rural areas of South China, South subtropical evergreen broad-leaved forest, tropical monsoon rain forest, Guangdong, Guangxi and Taiwan Province provinces. Function: clearing away heat and toxic materials, removing blood stasis and reducing swelling, mainly treating cassava poisoning. A topical medicine for treating furuncle.