A prickly-leaved and highly variable shrub, growing to 3 metres high, typically on clay-based or alluvial soils in dry sclerophyll woodland.
It is common on creeks and moist areas but can also be seen colonising roadsides in some places.
It grows primarily on the NSW central coast as well as all the tablelands regions, and up into south-eastern Queensland. There are a range of forms from different areas.
The leaves are linear from 5 to 35 mm long and only about 1 to 2 mm wide, terminating in a pungent point. In some forms the pungent tip is very sharp. This is generally a prickly plant.
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.
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. This species has flowers clusters of the typical ‘spider’ form, occurring in the leaf axils and at the ends of the branches. Flower colour may be greenish-yellow, yellow, apricot, pink or red. Individuals flowers are to 40 mm long,
The fruit is a follicle which is hairless (glabrous).
G. juniperina adapts easily to cultivation and grows in a wide range of soils and aspects in locations with good drainage and preferable full sun. There are some cultivars available – outlined below. It is quite hardy in a full sun position. Some forms can make a good ground hugging shrub whilst others are more upright. It likes a heavier soil but may do well on a sandy soil.
Prune lightly after flowering to encourage denser bushes.
In a garden situation, Grevilleas are good bird-attracting plants as copious quantities of nectar are produced.
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.
There are seven subspecies of Grevillea juniperina currently recognised in NSW:
• G. juniperina subsp. allojohnsonii – is found on the Northern Tablelands and North West Slopes in northern New South Wales. It is a prostrate shrub to 30 cm high with red flowers;
• G. juniperina subsp. amphitricha – is a prostrate or spreading shrub with yellow or orange flowers that grows to 1.2 m tall and 3 m wide. It is found between Braidwood and Nerriga in the Shoalhaven River catchment on the Southern Tablelands;
• G. juniperina subsp. fortis – is a vigorous red-flowered shrub growing to 3 m tall that is found on rocky hills and slopes near watercourses, mostly within the Australian Capital Territory;
• G. juniperina subsp. juniperina – grows as a spreading shrub to 1.5 m high and is endemic to Western Sydney, restricted to clay soils from Blacktown west to Penrith and Marsden Park and north to Pitt Town. It is listed as a threatened species (vulnerable) under State legislation. It has red to apricot to cream flowers;
• G. juniperina subsp. sulphurea is a shrub up to 2 m high that grows on alluvial soils and along riverbanks. It is found in the catchments of the Coxs, Kowmung, Wollondilly and Shoalhaven Rivers in the Central and Southern Tablelands, as well as Lidsdale to Jenolan State Forest in the southwestern Blue Mountains. It hybridises with G. juniperina subsp. trinervis in the southern and western Blue Mountains;
• G. juniperina subsp. trinervis – is a prickly shrub with a spreading or prostrate habit ranging from 0.5 to 1.2, or rarely to 2 m high, with yellow, orange or red flowers. It is found in the western Blue Mountains; and
• G. juniperina subsp. villosa– is an upright red- or yellow-flowered shrub up to 2 m high found along watercourses in eucalypt forest east and northeast of Braidwood, as well as Currockbilly in southeastern New South Wales.
There are a range of cultivars available such as ‘Molonglo’, ‘New Blood’, ‘Poorinda Queen’ and others
These have different flower colours and habits (see weblinks below).
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”.
G. juniperina plants are sometimes killed by bushfire, regenerating afterwards from seed. However, plants have been known to sucker vigorously in some populations after a disturbance event.
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.
juniperina – Latin – alluding to its juniper-like foliage (genus Juniperinus).
Only one subspecies, subsp. juniperina, is listed as threatened with extinction (with the category of Vulnerable at the State level). All other subspecies are considered to not be threatened in the wild.
NSW Flora Online (PlantNET) – Grevillea juniperina profile page
Gardening with Angus – Grevillea juniperina profile page https://www.gardeningwithangus.com.au/grevillea-juniperina-juniper-leafed-grevillea/
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.