Sphaeroblast - buds that never make a branch

A plane tree at the botanical garden in Hamburg was covered in knobbly wooden warts — I learned these are sphaeroblasts: dormant buds that thicken into rounded woody growths instead of extending into branches or foliage. The tree looked perfectly healthy, so I think of it more as a feature than ‘anomalous growth’ since it makes the trunk so unique.

But I’m not into as much into this type of tree behviour, so I can only argue from an aesthatic point of view: warts on a tree make it look old and venerable.