Freezing fog can leave icy spikes, called 'Pogonip' in the Western US, on leaves and branches of trees.
Definition of POGONIP:
a dense winter fog containing frozen particles that is formed in deep mountain valleys of the western United States
Origin of POGONIP - Shoshone paã i̵napp i̵h cloud; First Known Use: 1865
(REF: http://www.merriam-webster.com/dictionary/pogonip)
Definition of HOARFROST:
Hoarfrost is frozen dew, while Pogonip is frozen fog. (SEE: http://www.thefreedictionary.com/hoarfrost)
"hoar·frost (hôrfrôst, -frst, hr-) n. Frozen dew that forms a white coating on a surface. Also called white frost."