We call this sort of buildup on trees "Snow Ghosts" if it's from regular snow, so I guess these are Ice Ghosts:
(click for story and more photos)
(http://assets.inhabitat.com/wp-content/blogs.dir/1/files/2014/12/Marko-Korosec-Photos-Ice-Formations-Slovenia-6.jpg) (http://inhabitat.com/these-photos-capture-the-magic-of-slovenias-startling-ice-formations/)