Grevillea flexuosa

Tangled Grevillea / Zig Zag Grevillea

Family: Proteaceae

A shrub growing to 2 m tall with spreading/arching branches which can spread several metres wide.

It is a threatened species growing in Western Australia and is found naturally in the south-west region, north-east of Perth, typically growing in Jarrah Forest.

Leaves are dark green, to 130 mm long, and are divided into broad toothed-segments about 2 cm wide with prickly points, and are very architectural, somewhat reminiscent of some pin-oak leaves. At times, the new growth can have bronze tinges.

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 a shortly compact cylindrical raceme with inflorescences to about 6 cm long by 2 cm wide. They are bright cream to yellow, and can be produced profusely mainly in winter and spring. Inflorescences can be cream at the base and lemon-yellow further up, during the flowering period.

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.

The carpels are to 10 mm long, bright cream to lemon-yellow with darker yellow tips. The perianths are cream-white to lemon-yellow.

In the garden

Not the most hardy of grevilleas as it is found naturally on fast draining sands in low humidity. However, plants are sold as grafts where they are grafted onto a much hardier rootstock (eg: Grevillea robusta). This allows them to tolerate heavier soils.

It may be slow growing to start with and some members advise keeping it in a pot for several years before planting in the ground. It can have a horizontal-sprawling habit so provide some pruning to keep in check, and allow some room to spread.

The copious lemon-yellow inflorescences produced at the terminals combined with the dissected leaves makes it very attractive. Provide fast drainage and full sun to part-shade. It is excellent for attracting bees and other insects. Will tolerate light frost.

Two grafted plants have been growing successfully in Heather Miles’ Hunter Valley garden since 2006. Each August, the bushes are smothered in small yellow flowers which have a delicious honey scent.  She keeps them pruned to a tall mound. Occasionally as with any graft, the root stock tries to shoot and needs to be cut off. 

Propagation

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. Grafted forms are the best for east coast gardens.

Other information

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”.

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.

flexuosa – Latin for “flexuous”; the stems exhibit a zig-zag like pattern from node to node, creating a geometrical branching habit.

Threatened with extinction in the wild in Western Australia.

https://www.gardeningwithangus.com.au/grevillea-flexuosa-zig-zag-grevillea/
https://en.wikipedia.org/wiki/Grevillea_flexuosa
Wrigley, J.W. & Fagg, M.I. (2001). Australian Native Plants – Propagation, cultivation and use in landscaping. 4th edition. New Holland Publishers, Pty. Ltd. Australia.
https://florabase.dpaw.wa.gov.au/browse/profile/2007

By Dan Clarke