Osage orange

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A dioecious spiny tree (Maclura pomifera) native to the south-central United States, having round greenish inedible fruit and formerly used in hedgerows.

from the GNU version of the Collaborative International Dictionary of English.

• (Bot.) An ornamental tree of the genus Maclura (Maclura aurantiaca), closely allied to the mulberry (Morus); also, its fruit. The tree was first found in the country of the Osage Indians, and bears a hard and inedible fruit of an orangelike appearance. See bois d'arc.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun small shrubby deciduous yellowwood tree of south central United States having spines, glossy dark green leaves and an inedible fruit that resembles an orange; its hard orange-colored wood used for bows by Native Americans; frequently planted as boundary hedge