CLASSIFICATION
Kingdom: Plantae Order: Proteales Family: Proteaceae Genus: Grevillea Species: robusta Vernacular name: Silver oak
PLANT PROFILE:
Commonly known as Silkoak or Silk Oak, is a native Australian tree that grows quite well here in Tucson gardens. It has not naturalized in Arizona as it has in Hawaii or Florida because it requires a bit more water than desert natives, although it is drought-tolerant. Silk Oak is hardy to 17 °F (-8.3 °C). The leaves on this member of the Proteaceae family are large and fern-like, and the flowers are a brilliant yellow-orange. This tree is technically evergreen as it always has leaves, but there is a yearly leaf drop, so it can be a bit messy. These trees are fairly fast-growing and can reach 100 feet (30.5 m) at maturity. When they are flowering in the spring time, these trees attract the most colorful of birds like orioles, grosbeaks, tanagers, warblers, and humming birds. The flowers are not only filled with sweet nectar, they also attract numerous insects, and both are enjoyed by a wide variety of hungry birds. Its flowers are golden-orange bottlebrush-like blooms, between 8-15 cm long, in the spring, on a 2-3 cm long stem and are used for honey production. The seeds mature in late winter to early spring, fruiting on dark brown leathery dehiscent follicles, about 2 cm long, with one or two flat, winged seeds.
USES:
Before the advent of aluminium, the timber from this tree was widely used for external window joinery as it is resistant to rotting. It was also popular for making furniture. There are severe restrictions on the harvesting of this tree now as the number of trees became depleted. Silky Oak is a valuable timber and was one of Australia’s best known cabinet timbers. It is the best tree which can be used for fencing and it is one of the fastest growing trees.