Grevillea sphacelata

Grey Spider Flower

Family: Proteaceae

A shrub to 2.5 m high. It is found naturally, primarily in the Sydney basin, occurring from north of Sydney to north of Kiama and to Mittagong area. Then there are some disjunct records near the Jervis Bay as well as Gosford areas. It grows in dry sclerophyll heath, shrubland, woodlands and forests, on sand and sandstone.

Branchlets are silky.

Leaves are alternate along the stems, to 3 cm long and to 0.4 mm wide, margins entire, upper surface typically hairless and lower surface densely hairy with white 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 one of the spider-flowers with inflorescences a mixture of grey, brown and pink. Flowers all year but chiefly late winter–summer.

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 perianth is pale brown with grey hairs.
The carpels are to 12 mm long, style pinkish grey, hairy.

Follicles are about 1cm long with sparse hairs.

In the garden

Not overly common in cultivation but has likely increased as a cultivated plant over the last few decades. It is a former subspecies of Grevillea buxifolia which can be successfully grown and so it likely grows in a similar manner.

It would prefer a sandy soil with good drainage. Pruning after flowering would result in a rounded shape and dense growth.

Can be kept as a small shrub with pruning and has naturally dense foliage along stems.

Plant in full sun or part-shade for best results. Give supplementary water in very dry times.

In a garden situation, Grevilleas are good bird-attracting plants.

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

This species was previously known as Grevillea buxifolia subsp. sphacelata.

The common name “Grey Spider Flower” is applied to several grevilleas.

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.
sphacelata – from Ancient Greek “sphakelos” (σφάκελος) referring to gangrene or mortification, which refers to the black speckles on, and withered appearance of, the flowers.

Not considered at risk in the wild.

https://en.wikipedia.org/wiki/Grevillea
https://apps.lucidcentral.org/plants_se_nsw/text/entities/grevillea_sphacelata.htm
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~sphacelata

By Jeff Howes, edited Dan Clarke