Source : Webster's Revised Unabridged Dictionary (1913)

Queensland nut \Queens"land nut`\ (Bot.)
   The nut of an Australian tree ({Macadamia ternifolia}). It is
   about an inch in diameter, and contains a single round edible
   seed, or sometimes two hemispherical seeds. So called from
   Queensland in Australia.

Source : WordNet®

Macadamia ternifolia
     n : small Australian tree with racemes of pink flowers; widely
         cultivated (especially in Hawaii) for its sweet edible
         nuts [syn: {macadamia nut}, {macadamia nut tree}]