Normally if you see flowers on a tree they are growing on branches but there is one particular tree where flowers grow directly on the trunk.
It is common for the Redbud trees of North America to sprout flowers, on their trunk
In the Spring, the lovely pink flowers grow in nodal clusters and can develop on any part of the tree – the trunk, branches, or even twigs. This is known as “cauliflory”. And it is freaky but rather beautiful.
Source: Kansas State University