About Grevillea pteridifolia Knight
Grevillea pteridifolia Knight is most commonly a shrub or tree that typically grows 2 to 14 metres (6 feet 7 inches to 45 feet 11 inches) tall, and very rarely grows as a prostrate shrub. Its leaves are 100 to 450 millimetres (3.9 to 17.7 inches) long, and are usually pinnatisect, with between 13 and 29 linear or very narrowly egg-shaped lobes. These lobes are 150 to 250 millimetres (5.9 to 9.8 inches) long and 1 to 4 millimetres (0.039 to 0.157 inches) wide. The leaf edges are rolled under, and all exposed parts of the leaf's lower surface are covered in silky hairs. The flowers are arranged in clusters along one side of a central rachis that is 80 to 220 millimetres (3.1 to 8.7 inches) long, and flowers open first at the base of the cluster. The outside of the flowers is greyish-green to silvery, while the inside of the flower and the style are bright orange-yellow or reddish. The pistil of the flower is 23 to 36 millimetres (0.91 to 1.42 inches) long. Flowering can occur in most months of the year, with a peak flowering period from May to September. The fruit is a shaggy-hairy follicle that is 14 to 21 millimetres (0.55 to 0.83 inches) long. Populations of this species from Queensland are non-lignotuberous shrubs to small trees, with smooth bark and lighter-coloured inflorescences than other forms of the species. A prostrate form that can spread up to 5 metres (16 feet) across occurs in exposed areas near Cooktown in north Queensland. Populations from Western Australia and the Northern Territory grow as rough-barked, lignotuberous shrubs to small trees. One population of this rough-barked form in Kakadu National Park has entirely silvery leaves. Grevillea pteridifolia is distributed from the Kimberley region of Western Australia, across the Northern Territory, and into Queensland, where it grows along the Great Dividing Range as far as the area around Barcaldine. It occurs in regions that experience wet summers, dry winters, and between 500 and 1,500 millimetres (20 to 59 inches) of annual rainfall. Also known as golden grevillea, this species grows easily in cultivation in warm climates. It generally benefits from extra water during summer and grows best in well-drained soils. Its brittle branches can break during strong winds. Several popular garden grevillea cultivars are hybrids between Grevillea pteridifolia and other grevillea species. Grevillea 'Sandra Gordon' is a hybrid between this species and G. sessilis. Grevillea 'Honey Gem' is a cross between this species and a red form of Grevillea banksii. Similar to 'Honey Gem', G. 'Winter Sparkles' is another hybrid of G. pteridifolia and G. banksii. Aboriginal people living on Groote Eylandt traditionally used the leaves of this species as stuffing and as a herb when cooking emu. Early European settlers used the leaves to stuff pillows. A group of antibacterial compounds called kakadumycins have been isolated from a streptomycete that was recovered from G. pteridifolia.
