Osage trees are found in deciduous groves.
The plant and fruit are based on the real-life osage orange: https://en.wikipedia.org/wiki/Maclura_pomifera
Found in the savannah, osage is a type of mulberry with a large 40-60 foot trunk with dark bark and small leaves. The large lumpy fruit of osage trees is nonpoisonous but inedible and sometimes placed around houses to repel spiders.
Osage is prized for its heartwood, which ranges in color from orange to deep purple. Osage heartwood is so richly hued and finely grained that it needs no carving or ornamentation. Osage is highly prized for bowmaking.
Osage is not needed for alterations.