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  1. 89 Silky Oak
  2. 070_silky_oak_-_by_jim_harding_-_seed_pods Seed pods by Jim Harding
  3. 241_silky_oak_-_by_tatiana_gerus Flowers by Tatiana Gerus
  4. 023_silky_oak_-_by_jim_harding_-_leaves Leaves and no flowering by Jim Harding

Silky Oak

Grevillea robusta

Appearance

  • An evergreen tree.
  • Size: usually 20 – 30 m high but can range from 8 – 40 m in height.
  • Leaves: silvery green and fern-like, green on the upper surface and paler underneath. They are 10 – 34 cm long and 9 – 15 cm wide, and consist of 11 – 31 segments that are narrow-elliptic to triangular in shape. The segments are 1.5 – 5 cm long and 2 – 10 mm wide, and they give the leaf a deeply divided appearance.
  • Flowers: golden yellow to orange, each one is about 2 cm long but they are arranged in pairs along the flowering stalk to give an overall length of 12 – 15 cm. • Fruit/seed: a dark-brown, smooth seed pod, oval in shape and slightly flattened. It is about 2 cm long. 

What to Observe

  • First fully open single flower
  • Full flowering (record all days)
  • End of flowering (when 95% of the flowers have faded)
  • Not flowering

ClimateWatch Science Advisor

We expect plants to start shooting and flowering earlier in the year as a result of climate change warming the Earth. They may also start appearing in new areas, as warmer temperatures enable them to live in environments that were previously too cold for them.

When To Look

  • From September through to January
  • Flowers appear in spring (mainly from September to November but later in cooler areas)
  • Mature seed pods appear in December and January

Where To Look

  • It is naturally found on the coast and coastal ranges of southern Queensland and northern New South Wales, from Bundaberg south to Coffs Harbour, and to about 150 km inland. However, it is now relatively rare in its natural state.
  • In subtropical to dry rainforests, forests with tall trees and fern-like ground cover, and sometimes along stream banks.
  • It can also be found on higher slopes amongst conifer trees and vines. 
  • It grows in most areas along the east coast but needs shelter from the cold and frost when young.
  • Look in rainforests, on riverbanks and on dry hillsides amongst conifer trees and vines.

Silky Oak Occurrence Map ALA

References

Australian Biological Resources Study 1995. Flora of Australia Volume 16. CSIRO Publishing / Australian Biological Resources Study.

Australian Biological Resources Study 2000. Flora of Australia Volume 17A. CSIRO Publishing / Australian Biological Resources Study.

Links

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  1. What Else?

    The Silky Oak is a very distinct tree and unlikely to be confused with anything else.

  1. Did You Know?

    The Silky Oak was named in 1830 by an explorer and botanist, Allan Cunningham. The genus name, Grevillea, honours Charles F Greville who co-founded the London Horticultural Society, and the species name, robusta, refers to its large size

    Sawdust from the Silky Oak, and sometimes its foliage, can cause contact dermatitis.