Grevillea banksii, known by various common names including Red silky oak, Dwarf silky oak, Banks' grevillea, Byfield waratah and, in Hawaii, Kahili flower or Kahili tree is a plant of the large genus Grevillea

Grevillea

Grevillea is a diverse genus of about 360 species of evergreen flowering plants in the protea family Proteaceae, native to Australia, New Guinea, New Caledonia, and Sulawesi. It was named in honour of Charles Francis Greville. The species range from prostrate shrubs less than 0.5 m tall to trees...

in the diverse family Proteaceae

Proteaceae

Proteaceae is a family of flowering plants distributed in the Southern Hemisphere. The family comprises about 80 genera with about 1600 species. Together with the Platanaceae and Nelumbonaceae they make up the order Proteales. Well known genera include Protea, Banksia, Embothrium, Grevillea,...

. Native to Queensland

Queensland

Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...

, it has been a popular garden plant for many years though has been superseded somewhat horticulturally by smaller and more floriferous hybrids.

Taxonomy

Grevillea banksii was first described by the botanist Robert Brown

Robert Brown (botanist)

Robert Brown was a Scottish botanist and palaeobotanist who made important contributions to botany largely through his pioneering use of the microscope...

, who gave it its epithet in honour of Sir Joseph Banks

Joseph Banks

Sir Joseph Banks, 1st Baronet, GCB, PRS was an English naturalist, botanist and patron of the natural sciences. He took part in Captain James Cook's first great voyage . Banks is credited with the introduction to the Western world of eucalyptus, acacia, mimosa and the genus named after him,...

.

Description

It is a tall, slender or spreading shrub, or small tree up to 7 m (23 ft) high. Its leaves are pinnate

Pinnate

Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...

 with 3-11 deeply divided, linear to lanceolate segments 5-10 cm (2-4 in) long and 1 cm wide, with curled-back margins. Flowers are bright red or creamy-white, in clusters up to 15 cm (6 in) long. It flowers for most of the year, but mainly in winter and spring.

Distribution and habitat

Grevillea banksii is found on the Queensland coast from Ipswich

Ipswich, Queensland

Ipswich is a city in South-East Queensland, Australia. Situated along the Bremer River Valley approximately 40 kilometres away from the state's capital Brisbane. The suburb by the same name forms the city's Central Business District and administrative centre...

 to Byfield National Park

Byfield National Park

Byfield is a national park in Queensland, Australia, 35 km north of Yeppoon....

. It grows on headlands, ridges and forest.

Cultivation

Various forms of Grevillea banksii have been in cultivation for many decades, however it is less seen now than previously as it has been replaced by smaller, more compact, hybrids such as G. 'Robyn Gordon'

Grevillea 'Robyn Gordon'

Robyn Gordon is also a driver in All-American Girl Racing.Grevillea 'Robyn Gordon is a very popular grevillea cultivar which has been planted widely in Australia and other countries....

 and G.' Superb'

Grevillea 'Superb'

Grevillea 'Superb is a widely grown grevillea cultivar bred by Merv Hodge in Queensland. It is a hybrid of a white-flowered Grevillea banksii, from Queensland, and the Western Australian plant G...

. These newer plants are more compact and have longer flowering periods and are more in demand in the era of the shrinking garden.

Grevillea 'Ruby red' is a prostrate red flowering form of uncertain origin which is in cultivation, often grafted onto Grevillea robusta

Grevillea robusta

Grevillea robusta, commonly known as the southern silky oak or Silky-oak, or Australian Silver-oak, is the largest species in the genus Grevillea. It is a native of eastern coastal Australia, in riverine, subtropical and dry rainforest environments receiving more than 1,000 mm per year of...

.

However, it has left a rich horticultural legacy, being one of the parents of G. 'Robyn Gordon', which has been one of the most commercially successful garden plants in Australian horticultural history. It is also parent of other garden plants Grevillea 'Honey Gem

Grevillea 'Honey Gem'

Grevillea 'Honey Gem is a grevillea cultivar originating from Queensland in Australia.It is a shrub that grows up to in height and has deeply divided dark green leaves that are approximately long and wide The inflorescences are yellowish orange racemes that are about long and wide...

', G. 'Superb', G. 'Misty Pink', G. 'Pink Surprise', and possibly G. 'Moonlight

Grevillea 'Moonlight'

Grevillea 'Moonlight' is a widely cultivated and popular garden plant in Australian gardens and amenities.It was a selected form of the Queensland species Grevillea whiteana, although this has been questioned because of the difference in appearance to the parent plant...

'.

Toxicity and allergic reactions

The flowers and seed pods contain toxic hydrogen cyanide. The alkyl resorcinols in G.banksii and Grevillea 'Robyn Gordon' are responsible for contact dermatitis

Contact dermatitis

Contact dermatitis is a term for a skin reaction resulting from exposure to allergens or irritants . Phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight....

.