Natal plum

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

• noun A South African evergreen shrub (Carissa macrocarpa) often cultivated as a hedge plant, having forked spines, white flowers, and edible scarlet berries.

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

• (Bot.) The drupaceous fruit of two South African shrubs of the genus Carissa (formerly Arduina) (Carissa bispinosa and Carissa grandiflora). It is also called amatungulu.
• the shrub bearing the natal plum{1}; a very large closely branched South African shrub (Carissa grandiflora) of the dogbane family having forked bright green spines, white flowers, shiny leaves, and red berries.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Any of several South African evergreen shrubs, of the genus Carissa, having white flowers and red berries, often cultivated as hedging

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

• noun South African shrub having forked spines and plumlike fruit; frequently used as hedging
• noun edible scarlet plumlike fruit of a South African plant
• noun very large closely branched South African shrub having forked bright green spines and shiny leaves