Grevillea acanthifolia is a spreading shrub that may reach a height of 3 metres with a spread of 4 metres.
It occurs solely in NSW, in three largely disjunct patches; on the northern, central and southern tablelands-coastal divides. Three subspecies are recognised, based on these disjunctions:
Leaves are generally stongly pinnatisect (divided), to 10 cm long and 7 cm wide, with prickly tips (holly-like), dark green. New growth can be brilliant red.
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 “toothbrush-type” with red inflorescences, to 10 cm long by 3 cm wide, appearing predominantly from October to February.
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; grey to purple and hairy.
The carpels are up to 3 cm long, is a pink to maroon in colour, and tipped with a yellow to green pollen-presenter.
The fruit is a follicle, hairy without dark stripes or blotches.
Grevillea acanthifolia carries pink, toothbrush-type flowers for most of the year.
Judicious pruning will keep plants to a more manageable height and width. If pruned well – plants can be very attractive.
Grevillea acanthifolia subsp acanthifolia is the most commonly cultivated subspecies and has proved to be a hardy, free-flowering, bird-attracting shrub.
It has very prickly foliage and perhaps should not be planted near paths. Can tolerate more shade than most other grevilleas. Usually hardy in most situations. May benefit from additional watering in very hot and dry times.
Propagate from cuttings.
The type specimen was collected in the Blue Mountains during John Oxley’s first expedition in 1817. The species was named by Alan Cunningham in 1825. The thumbnail is the illustration of the type specimen.
There is a record of Grevillea acanthifolia subsp. acanthifolia in cultivation in a London nursery in 1893.
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.
acanthifolia – Latin – referring to the foliage resembling species of Acanthus (a genus of about 30 species from the Northern Hemisphere).
(subsp. paludosa) – Latin – meaning “marshy” referring to the swamp-habitat of this subspecies.
(subsp. stenomera) – from Greek stenos (στενός) – meaning “narrow” and –meros (μέρος) meaning “part” – referring to the narrow leaf segments of this subspecies.
One of the subspecies – subsp. paludosa, is listed as at risk of extinction in the wild, at both the State and Commonwealth level, with the category of Endangered.
NSW Flora Online (PlantNET) – Grevillea acanthifolia profile page https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~acanthifolia
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
Australian Native Plants Society Australia – Grevillea acanthifolia profile page https://anpsa.org.au/plant_profiles/grevillea-acanthifolia/