Grevillea speciosa is a small to medium shrub that may reach a height of 2 metres, with a spread of around 1 metre.
It is a species pretty much confined to the Greater Sydney Basin, growing north of Port Jackson (not south of), to around Kulnura (north of Gosford) (Yengo NP-area) and Wyong-area.
It typically grows on Hawkesbury Sandstone, often on very shallow sandy soils as well as sandstone platforms, in wet and dry heath, as well as dry sclerophyll woodland and forest.
Leaves are narrow-lanceolate or elliptic, light to dark green, and up to 5 cm long by up to 1.5 cm wide with a mucro, with silvery hairs underneath.
A grevillea inflorescence is technically a cluster of paired flowers, termed a conflorescence with the overall structure forming a raceme-like appearance. Grevillea species exhibit 3 main inflorescence structures:
1. A cylindrical to ovoid raceme (with flowers emerging around a 360° radius)
2. A single-sided raceme (with flowers produced on only one side, resembling a tooth-brush)
3. A condensed or clustered raceme (usually as long as it is wide, with species referred to as the spider-flowers).
Grevillea mostly produce the inflorescences at the terminals, beyond the foliage, which differs to the closely related Hakea.
This species is a spider-flower with bright red inflorescences, appearing over most of the year but primarily in spring. Each cluster measures to 7 cm wide and about 4 cm long.
Individual flowers are composed of 1 carpel (female part) where the style and stigma protrude out; 4 stamens hidden away in the perianth; and the perianth (petals and sepals collectively) which connects to a pedicel. Proteaceae flowers do not have any discernible petals or sepals (having only one whorl) and so these are referred to as “tepals” of which there are 4. In this species, the perianth is up to 2 cm long; red to rarely pink.
The carpels are up to 3 cm long, red to rarely pink in colour, and tipped with a red pollen-presenter.
The fruit is a follicle, without hairs.
Author’s notes: In our cold climate garden, specimens reach a height of about 1 metre after 3 years in the ground.
Grevillea speciosa is a beautiful shrub with eye-catching blooms. It is reported to be a hardy shrub in most situations. Plant in full sun, on a sandy soil for best results. It may tolerate heavier soils. It does grow naturally in wet sandstone heath (as well as other drier areas) and so may not be overly fussy about drainage.
The species appreciates light pruning. This keeps the plants dense and blooming bounteously.
We have admired this beautiful grevillea in the Brisbane Waters National Park near Gosford on the Central Coast of NSW.
Propagate from cuttings.
Grevillea speciosa is said to hybridise with Grevillea sericea and Grevillea oldei.
Grevillea is a diverse genus of about 360 species of evergreen flowering plants native to rainforest and more open habitats in Australia, New Guinea, New Caledonia, Sulawesi and other Indonesian islands east of the Wallace Line. NSW currently has about 85 species although with a lot of subspecies and some informal taxa recognised.
Grevillea flowers were a traditional favourite among First Nations Peoples for their sweet nectar. This could be shaken onto the hand to enjoy, or into a coolamon with a little water to make a sweet drink. They might be referred to as the original “bush lollies”.
Most Grevillea species will regenerate from seed after fire but can produce copping shoots.
Grevillea – was named in honour of Charles Francis Greville (1749-1809), an 18th-century patron of botany and co-founder of the Royal Horticultural Society. He was also a British antiquarian, collector and politician who sat in the House of Commons from 1774 to 1790.
speciosa – Latin – speciosus meaning “beautiful” – referring to its bright red flowers which can put on an attarctive display.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Grevillea speciosa profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~speciosa
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Wikipedia – Grevillea speciosa profile page https://en.wikipedia.org/wiki/Grevillea_speciosa