F. Muell., a distinct different species, bearing small, bitter, cyanogenic seeds less than 1.3 cm in diameter, inedible and never cultivated. Many cultivars have been developed and grafted trees of promising selections have been made. Most of the Australian crop is based upon M. tetraphylla , with some orchards of grafted M. integrifolia varieties. Teddington' is a hybrid with thin shell. Introduced in other parts of tropics, as Ceylon, and commercially grown in Hawaii and France, at medium elevation.
Macadamia grows best in rainforest areas, along coasts with high humidity and heavy rainfall.
However, it is tolerant of adverse conditions when once established. Inland, tree thrives in some localities but crops are usually lighter than when grown near coast. Under orchard conditions, trees are shapely, robust, and more heavily foliaged than they are in rainforest. Grows well on wide range of soil, but fails on infertile coastal sands, heavy clays or gravelly ridges. Yields well on deep, well-drained loams and sandy loams.