I am very baffled with this; well below the trunk of this boxwood a new strange leaf is sprouting.
I made sure it is growing from the trunk, near the rootbase.
As a comparison I shot the picture with a regular leaf from the same boxwood, which is completely different.
Any hints? Picture below ->
That is a piece of grass. The seed likely lodged in the bark of the boxwood and has had enough moisture to germinate. Remove it. It is a weed. left to grow its roots will push off the bark of the boxwood. Boxwood bark has deep crevices and sometimes flakes off partially, leaving gaps between it and the trunk of the plant. Not unusual to get this kind of thing.