Grevillea caleyi

Caley's grevillea

Family: Proteaceae

A shrub to 3 m tall up to 4 m wide with long spreading branches.

It grows in a small restricted area, approximately 8 square km, on Hawkesbury sandstone around Terrey Hills, 20 km or so north of Sydney NSW. It occurs in three major areas of suitable habitat, namely Belrose, Ingleside and Terrey Hills/Duffys Forest within the Ku-ring-gai and Northern Beaches Local Government Areas.

Leaves are covered in soft, rusty hairs and are alternate along the stems, comparatively large in size, to 18 cm long and to 8 cm wide. The leaves are somewhat unique, resembling a compound pinnate leaf, deeply divided with usually many spreading and paired elliptic lobes.

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 tooth-brush grevilleas, with rich burgundy-red inflorescences, to 8 cm in colour, flowering mainly in winter and 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. The carpels are to 40 mm long and red to red-pink with green tips.

The fruit is a follicle, about 1 cm long, usually hairy and with reddish-brown stripes or blotches.

In the garden

Worth growing, in well drained soils if plants can be sourced. It is known to be cultivated at some local nurseries for bushcare and conservation purposes.
Cultivation would be a way to preserve this rare plant with its beautiful foliage and attractive flowers. It also tolerates some shade and has an attractive habit. Give good drainage for best results. The rusty hairs on leaves and stems are also an added feature.

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

Propagation

Grevilleas are propagated by three principal methods; seed, cuttings and grafting. Tissue culture has also been used with a few species and cultivars but this is a more specialist method which is not of practical interest to most amateur growers. 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 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”.

Killed by fire and relies entirely on seed that is stored in the soil for regeneration. 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.

caleyi – named after George Caley, an amateur botanist sent to Australia to collect specimens by Joseph Banks. After Caley’s death in 1829, Brown (1830) published a paper on the Proteaceae, naming Grevillea caleyi, a plant, now rare, first found by Caley in 1805 near Belrose.

This species is threatened with extinction in the wild with a critically endangered listing at both State and Commonwealth level.

https://en.wikipedia.org/wiki/Grevillea
https://www.environment.nsw.gov.au/threatenedspeciesapp/profile.aspx?id=10361
https://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea%7Ecaleyi

By Jeff Howes, edited by Dan Clarke