Grevillea sericea

Pink Spider Flower, Silky Grevillea

Family: Proteaceae

A shrub to 2 metres high with about a 1 metre spread. An endemic to NSW, it grows naturally from southern Sydney to near Newcastle; west to the Blue Mountains area and north-west to the Goulburn River catchment in the Hunter Valley. It can be found in dry sclerophyll woodlands and forest as well as heathlands and shrublands, on sandy soils on sandstone.

Leaves can be variable, with a few different forms existing, elliptic to oblanceolate or close to linear, to 9 cm long and about 1 cm wide, margins entire and recurved, lower surface with silver silky hairs.

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 another of the “spider-flowers” with flowering occurring over a long period from autumn through to spring. Inflorescences are typically light pink but vary to deep-pink, reddish-pink, mauve and white; to 6 cm long by a few centimetres wide. Flowering can be prolific in this species.

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 20 mm long with pink styles (rarely white, mauve or reddish-pink). The perianth is similar in colour.

The fruit is a follicle, about 1 cm long, without hairs.

In the garden

This grevillea is popular in cultivation, especially with native plant lovers, and grows well when placed in a suitable position.

For Sydney-siders, it is one of the best local grevilleas to grow. Needs to be planted in full sun or part-shade and is reported to be frost tolerant. Plant on a sandy or well-drained soil for best results. Poor drainage tends to kill it off. Works well on a sloping garden.

Prune after flowering to promote denser growth, more flowering at the terminals, and a desired shape. This plant can be shaped into a symmetrical shrub.

There is a hybrid form available known as “Colloroy Plateau” – which has stemmed from G. sericea subsp. sericea and G. speciosa and has deeper pink flowers.

Some forms exhibit a suckering habit which can mean the plant may spread through a garden but is easily controlled if required.

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.

Other information

There are two sub-species recognised:
• subsp. sericea – leaves usually less than 3 cm long; pink or white flowers
• subsp. riparia – leaves up to 12 cm long; deep pink to purple flowers. This taxon occurs generally along rivers and streams in the lower Blue Mountains, west of Sydney.

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 coppicing 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.
sericea – from Latin sericeus, meaning “silky”, referring to the hairs on the underside of the leaves.

Not considered to be at risk in the wild at the species level although subsp. riparia is classified as threatened under the Rare or Threatened Australian Plants system due to its restricted distribution.

https://en.wikipedia.org/wiki/Grevillea
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~sericea
https://www.gardeningwithangus.com.au/grevillea-sericea/

By Jeff Howes, edited Dan Clarke