Athertonia is a genus of tall trees, constituting part of the plant familyProteaceae. It is a monotypic taxon, and the sole described species is Athertonia diversifolia, commonly known as Atherton oak. It is a small to medium-sized tree and is endemic to restricted tablelands and mountainous regions of the wet tropics rain forests of north-eastern Queensland, Australia, where it is widespread. For example, it grows in the Atherton Tableland region with which it shares its name, from the colonial pastoralist John Atherton. Its closest relatives are Heliciopsis and Virotia. A relative of the macadamia, it has potential as an ornamental tree and has an edible nut.
Taxonomy
Athertonia diversifolia was first described by Queensland Government Botanist C.T. White in 1918, who gave it the specific name derived from the Latindiversi- "different" and folium "leaves", from the fact that different-shaped leaves may be found on the one plant. He placed it in the genusHelicia. The Dutch botanist Hermann Sleumer placed it in the genus Hicksbeachia in 1955, where it stayed until Johnson and Briggs placed it in its own genus although conceded it was related to the former genus. Thus, it is the only member of the monotypic genusAthertonia. Common names include Atherton almond, Atherton Oak, White Oak, or cream silky oak.
Description
Athertonia diversifolia grows as a tree tall. The trunk may be buttressed and reaches a diameter of. Juvenile leaves are a simple oblong shape with finely toothed margins but are replaced by large lobed intermediate leaves which reach long. The adult leaves are variable in shape, lobed or entire, long and wide. Young branches and new growth are covered in fine rusty hair. Occurring from March to June, the flowers are cream and brown in colour and borne on long racemes. The lens-shaped fruit is long by wide and thick, dark blue, containing a woody-shelled nut with a large edible and crunchy kernel, which ripen in spring.
Distribution and habitat
Athertonia diversifolia is found in north Queensland from Cape Tribulation south to Mt Bartle Frere. Its habitat is rainforest, generally from in altitude. but is found at at Alexandra Creek. Much of its former habitat has been cleared. The soils are deep volcanic loams.
Uses
Atherton almond is cultivated to a limited extent for its edible nut, but makes a good specimen tree in large parks and has potential as an indoor foliage plant, or as a foliage plant in the cutflower industry. The species is readily propagated by seed. Athertonia diversifolia is the floral emblem of the Atherton shire in north Queensland. It is known as the Atherton oak due to the shape of its immature leaves which resemble those of the English oakQuercus robur, to which it is unrelated.
