Grevillea willisii is a spreading shrub reaching a height of 3 metres and can spread to 5 metres. Stems are covered with hairs.
It is native of north/north-eastern Victoria, in the Mitta Mitta Creek catchment, as well as Narlel Creek and Wheelers Creek, in the Omeo area. It grows on granite-rocky areas in alpine woodlands and forests.
It is a rare species and is listed as being threatened with extinction under Victorian legislation.
Leaves are grey-green, stiff and lobed with hairy lower surfaces; to 3 cm long and 2 cm wide; pinnately lobed or pinnatifid with up to 10 lobes per leaf and with lobed terminating in up to 3 “prongs” or secondary lobes with somewhat prickly tips.
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 has toothbrush inflorescences; creamy-white in colour, to 9 cm long by about 3 cm wide; predominantly in Spring.
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 perianths are up to 1 cm long; white-cream.
The carpels are up to 2 cm long, white-cream with a white pollen presenter.
The fruit is a follicle, hairy with purple-brown colourings.
Grevillea willisii, in our cold climate garden, has proved to be hardy, free-flowering, frost tolerant and with low water requirements once established.
It can be grown in full sun to heavy shade. Soil needs to be well drained. It is a useful screen plant and shrub-groundcover. The flowers are said to be not overly showy, but a nice plant nonetheless.
Prune after flowering to encourage a denser plant. It can spread to 5 metres wide, so allow some room.
Propagate from cuttings treated with hormone gel. We use red Clonex for all cuttings.
There are two forms. The typical form has short leaves, up to six centimetres long and develops into a spreading shrub. The long-leaved form grows into a small tree with leaves up to 14 centimetres long. This form may be extinct.
We first saw the species in the National Botanic Gardens, Canberra during a trip south. The plants were so impressive that it went down on our “must acquire” list. Fortunately we came across the species, in a Canberra nursery, during the same trip.
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.
willisii – Latin – named after James Hamlyn Willis (1910-1995), Australian Botanist who was the Acting Director of the Royal Botanic Gardens, Melbourne, 1970-1972 and who published many new plant species.
This species is listed as threatened in the wild in Victoria with the category of Endangered.
Australian National Herbarium – Grevillea willisii profile page https://www.anbg.gov.au/gnp/gnp12/grevillea-willisii.html
VICFlora – Flora of Victoria Online – Grevillea willisii profile page https://vicflora.rbg.vic.gov.au/flora/taxon/5ef41f6a-2eeb-4427-a784-21208efb7832
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.