Forest 51 - Silky Oak


Grevillea robusta

Grevillea robusta leaves. Photo not from the Arboretum, by L. Hawkes Grevilliea robusta leaves and flowers. Photo not from the Arboretum, by L. Muldoon (2)

Origin of the species name

Grevillea honours Charles F. Greville, co-founder of the Royal Horticultural Society in London; robusta from Latin meaning hard, strong or robust with reference to it being the largest of the grevilleas.

Family

Proteaceae

Date planted

October 2009

Lifespan

Mature street plantings in Canberra suggest that silky oaks can have a fairly long lifespan.

Grevillea robusta tree. Photo not from the Arboretum, by L. Hawkes

General description 

This is a fast-growing, single-stemmed, semi-deciduous tree, losing most of its leaves just before flowering. The bark is dark grey and furrowed in a lace-like pattern. The leaves can be over 30 cm long, fern-like, green on the upper surface and pale and silky below. The bright orange flowers are borne in many pairs along flower spikes. The flowers produce plenty of nectar so is very attractive to birds, bees and other insects. Height 25m Spread 15m.

Natural distribution and habitat

The species is native to northern New South Wales and southern Queensland, Australia where it occurs naturally in two distinct habitats, either in riverine rainforest on alluvial soils or in drier vine forest where it can occur on dry exposed hillsides.

Conservation status

Although this species is not classified as threatened, it is now relatively rare in its natural stands. 

Planting pattern

Planted in rows following the contours and occupying both sides of Forest Drive.

Uses

Before the use of aluminium, the timber from this tree was widely used for external window joinery as it is resistant to rotting. Due to the diminished supply in the wild, its use in Australia for furniture has now been curtailed. It has also been used for making musical instruments. The flowers are a rich source of nectar for honey.

Further reading

Boland DJ, MIH Brooker, GM Chippendale, N Hall, BPM Hyland, RD Johnston, DA Kleinig, MW McDonald and JD Turner (2006) Forest Trees of Australia (5th Edition) CSIRO Publishing.