Grevillea obtusiflora

Grey Grevillea

Family: Proteaceae

A spreading shrub, to 2 m high, sometimes suckering from roots (producing ramets or clones).
Grows in sandy loam soils in open lower mid-storey in dry sclerophyll forest in the Kandos and Capertee Valley areas of NSW (Central Tablelands). There are also a few other records near Armidale and Canberra.

It is restricted in the wild and listed as threatened with extinction.

Leaves narrow-elliptic, to 6 cm long to 1 cm wide, margins entire, lower surface loosely covered with long to shorter silvery 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 spp. mostly produce the inflorescences at the terminals, beyond the foliage, which differs to the closely related Hakea.

This species is a spider-flower. Inflorescences are often curved downward and can be up to 3-branched and 2 to 18-flowered, red in colour.

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 reddish, often with green or yellow towards base, pubescent outside, bearded usually above the middle inside. The carpel (female part) protrudes to 30 mm long with the ovary densely hairy and with the style red, with a green pollen presenter at the tip.

The fruit is a follicle, usually hairy, without dark stripes or blotches.

In the garden

There are a few cultivated hybrids available with this plant as a parent and they are worthy garden plants.

This plant is not overly common in cultivation but could be tried if plants could be sourced.

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

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

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”

Response to fire is unknown but likely regenerates from root zone suckering.

There are two subspecies currently recognised, both of which are considered endangered:
subsp. obtusiflora: a rhizomatous low shrub 0.2 to 0.3 m high and is sterile. It is restricted to Clandulla State Forest near Kandos.
subsp. fecunda: a rhizomatous shrub to 0.3 to 0.7 m high (rarely to 2 m high) and fertile, occuring in the Capertee Valley, north-west of Lithgow, and south into Gardens of Stone National Park.

This species is listed as threatened with extinction (Endangered) at both the State and Commonwealth level.

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.
obtusiflora – Latin – for blunt or thick, referring to the nature of the perianth segments

https://en.wikipedia.org/wiki/Grevillea
https://www.environment.nsw.gov.au/threatenedSpeciesApp/profile.aspx?id=10372
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~obtusiflora

By Jeff Howes, edited Dan Clarke