Most fruit trees have thorns they must be planted from the fruit itself because the trees you purchase at a nursary are bred to not have thorns. the tree uses its thorns to protect its fruit from other animals. the only wild fruit tree that does not have thorns is the fig tree.
Orange Trees
There are no apple trees that have thorns. There is a tree called the Hawthorn Thornapple tree that has thorns as its name suggests.
I have a mature tree with thorns over 3" long.
Well, depending on the kind of lemon tree. Most do have thorns, but the thorns usually decrease as the tree gets older.
Mesquites
I purchased and planted the tree 04/10. At that time I was not aware of any thorns. The tree now (08/10) has 2 more branches growing from the base of the trunk and they both have thorns.
Apparently the wild pear tree or common pear has wicked thorns at the end of new branch shoots.
thorns
The tree that has large thorns and yellow, fuzzy fruit is called the Poncirus trifoliata. The species was introduced from China.
The Wild Pear Tree and the Common pear has wicked thorns .
The Pygmy Date Palm has thorns on the bottom, but there are several that do...
thorns
A bramble.