Grevillea arenaria is a large shrub that can reach 4 metres tall and can spread to more than 5 metres wide.
It grows in NSW, from the central and south coast, to the northern and central western slopes subdivisions.
Two subspecies are recognised:
It grows in sandy soils in rocky situations, in open sclerophyll woodland and forest.
The leaves are light green to grey-green, soft and have a velvety feel; to about 80 mm long and about 15 mm wide, shortly lanceolate to elliptic.
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 would be considered a spider-flower; however, there are typically very few flowers in the inflorescences. Up to 10 flowers are in each cluster (sometimes only 2), to 6 cm wide and 3 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; pink, red or orange with a green or yellow base.
The carpels are to 3.5 cm long, green to grey-green with a darker green pollen presenter.
The fruit is a follicle, hairy without dark stripes or blotches.
Grevillea arenaria subsp. arenaria reaches a height between three to four metres in our cold climate garden. Some of our specimens are at over ten years old and have survived and thrived with a minimum of supplementary watering.
Birds use the dense foliage for nesting. The foliage is the most attractive feature of the species. Grevillea arenaria subsp. arenaria is a durable native plant. It is reputed as one of the most reliable grevilleas.
Our specimens produce plenty of seeds with many seedlings germinating in our garden. The soft foliage could be used as filler in cut flower arrangements. Our original specimens were grown from cuttings collected from a plant near Goulburn in southern New South Wales.
It is an excellent gap filler and can occupy a large area, so give some room to spread. Plant in a sunny spot with reliable drainage for best results.
The population in the Gilgandra area, central NSW, which is subsp. canescens, is of particular horticultural interest. These plants reach a maximum height of one metre with attractive velvety foliage and well-presented red flowers. Perhaps this population is different enough to be considered another subspecies or even a species in its own right. We grow the Gilgandra form in our cold climate garden and it has proved to be hardy and free flowering. Both foliage and flowers are attractive features. The Gilgandra form is said to sucker. Our plants have not shown any evidence of suckering.
This form would make an excellent addition to native rockeries and cottage gardens.
Grevilleas are propagated by three principal methods; seed, cuttings and grafting. To maintain desirable characteristics of a particular plant, vegetative propagation (e.g. cuttings or grafting) must be used. This also applies to propagation of named cultivars.
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.
arenaria – Latin – meaning “sandstone” – relating to the common habitat of this species.
(subsp. canescens) – Latin – meaning “grey-ing” or “grey-ed” – referring to the colour of the foliage.
This species is not considered to be at risk of extinction in the wild.
NSW Flora Online (PlantNET) – Grevillea arenaria profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~arenaria
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Mallee Design – Grevillea arenaria profile page https://malleedesign.com.au/outstanding-grevillea-arenaria/