oak! Olive.
oak tree Okame Cherry
There are a few trees that start with the letter "O" including:OakOliveOrangeOregon MyrtleOsage Orange
no there are not
Overalls
orchid is one
O (Othello) (2001)
Eucalyptus, elm, evergreen and eastern white pine are trees. They begin with the letter e.
Omaha, Nebraska starts with "O."
Oxygen and osmium are chemical elements. They begin with the letter O.
Ominous
Oxford