This sort of corky wings is totally normal in some kinds of elms. In young strong shoots appears like protection mostly on the base. The cork stands for a while, but finally disapear blending whit the bark when the branch thicken or falling apart when time goes on. You can see one of my english elms,arround the minute ten, in this video
click,click, with this feature in a 2 years sacrifice branch, but no cork in some areas, and neither in the main trunk.
Young branch one year old
One branch one year old on the left, one 2 years and half old on the right
main trunk age unknown
Greetings from Spain.