Macadamia tetraphylla

Macadamia tetraphylla is a species of tree in the family Proteaceae, native to southeastern Queensland and northeastern New South Wales in Australia. It is known by the common names rough-shelled macadamia or Queensland nut.

Description

Macadamia tetraphylla is an evergreen tree that grows up to 18 meters tall. The leaves, which are always in whorls of three or four, are 7.5–25 cm long and 2–4 cm wide with toothed margins. The flowers are arranged in spikes or racemes 5–10 cm long. The fruit is a hard, woody, globose follicle with a pointed apex, containing one or two seeds.

Taxonomy

The species was first formally described by the botanist Ferdinand von Mueller in 1857. The specific epithet (tetraphylla) is derived from the ancient Greek words tetra- meaning "four" and -phylla meaning "leaves".

Cultivation

Macadamia tetraphylla is commercially grown for its nuts. The nuts are a valuable food crop in Australia and are also exported to Japan, Europe, and North America. The tree is also grown as an ornamental for its glossy foliage and attractive flowers.

Ecology

The tree is a key species in the rainforest ecosystems of eastern Australia, providing habitat and food for a variety of wildlife. It is also a host plant for the larvae of the macadamia nut borer and the macadamia lace bug.

Conservation

Macadamia tetraphylla is listed as vulnerable by the IUCN. Threats to the species include habitat loss due to land clearing for agriculture and urban development, as well as predation of the nuts by introduced species such as rats and possums.

See also

• Macadamia integrifolia
• Macadamia ternifolia