What do the following names, words, and phrases have in common?

ETHEL MERTZ
TIPPECANOE
INFIRMARY
PRANCED AROUND
BURMA SHAVE
PRESOAKED

HINT:
The answer involves hidden words.

Answer:

Each clue conceals the name of a tree:

ethEL Mertz
tipPECANoe
inFIRmary
pranCED ARound
burmA SHave
presOAKed

Credit: NY Times Crossword
Samuel A. Donaldson - Oct. 5, 2014
TIMBER!