Grevillea robusta A. Cunn. ex R. Br.

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Credits

Article from New Trees, Ross Bayton & John Grimshaw

Recommended citation
'Grevillea robusta' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/grevillea/grevillea-robusta/). Accessed 2020-11-28.

Genus

Common Names

  • Silky Oak

Glossary

strobilus
Cone. Used here to indicate male pollen-producing structure in conifers which may or may not be cone-shaped.

References

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Credits

Article from New Trees, Ross Bayton & John Grimshaw

Recommended citation
'Grevillea robusta' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/grevillea/grevillea-robusta/). Accessed 2020-11-28.

Vigorous, long-lived tree 15–40 m. Bark greyish brown and fissured. Branchlets angular and rusty-tomentose. Leaves fern-like, 10–34 × 9–15 cm, bipinnate or tripinnate, with 11–24(–31) primary lobes, lobes entire or divided, ultimate lobes 0.5–5 × 0.2–1 cm, upper surface glabrous or with sparse silky hairs, lower surface silky to tomentose, margins recurved; petiole 1.5–7 cm long. Inflorescences erect, terminal and simple or with up to four branches, each spike 12–16 cm long with many flowers. Flowers golden-yellow to orange outside, inside with red dots; tepals 0.6–0.7 cm long; style yellow-orange, 2–3 cm long. Fruit a follicle, laterally compressed, 1.2–1.6 × 1 cm. Flowering September to November (Australia). McGillivray 1993, Olde & Marriott 1995, Makinson 2000. Distribution AUSTRALIA: northeastern New South Wales, southwestern Queensland. Habitat Three distinct habitats: gallery rain forest and forest margins with Castanospermum australe A. Cunn. & C. Fraser ex Hook.; riverine evergreen forest with Casuarina cunninghamiana; and Araucaria cunninghamii forest on steep slopes and hills. USDA Hardiness Zone 9–10. Conservation status Not evaluated. Illustration NT382. Cross-reference K118.

This fine tree is by far the most commonly cultivated Grevillea, being grown in plantations and as a street or shade tree throughout the tropics and subtropics, and giving serviceable timber. It is also very much the biggest member of the genus, and one of only a handful to form straight-trunked trees. When in flower it is a wonderful sight. In our area it is at the edge of its tolerance, but is not a hopeless case. There is a 12 m tree in Brynmill Park, Swansea which has survived the removal of its originally protective greenhouse, and trees up to 9 m have been recorded in Devon (Johnson 2007, TROBI). Other specimens may be accidental survivors of bedding schemes in which young plants were used as centre-pieces, as in the case of two growing outside Rotherhithe Police Station. Although showing signs of frost damage, the larger of these two trees was 8.5 m in 2005 (TROBI). It is worth a try in maritime situations in our area, where it should be given a site in full sun in moist soil. It becomes hardier with age, so young plants (grown from seed) should be protected for their first few winters, but adult trees can survive temperatures down to –7 ºC (Moore 2004).