About

Banksia dentata, commonly known as the tropical banksia, is a species of tree in the family Proteaceae. It occurs across northern Australia, southern New Guinea and the Aru Islands. Growing as a gnarled tree to 7 m (23 ft) high, it has large green leaves up to 22 cm (8.7 in) long with dentate margins. The cylindrical yellow inflorescences, up to 13 cm (5.1 in) high, appear between November and May, attracting various species of honeyeaters, sunbirds, the sugar glider and a variety of insects. Flowers fall off the ageing spikes, which swell and develop follicles containing up to two viable seeds each.

Banksia dentata is one of four Banksia species collected by Sir Joseph Banks in 1770, and one of the four species published in 1782 as part of Carolus Linnaeus the Younger's original description of Banksia.

How to grow it

The tree's gnarled bark, large green leaves, and yellow flower spikes are attractive horticultural features. B. dentata is vulnerable to cold winters in cultivation in Melbourne and recovers over the hotter months of summer. It has not been grown in colder climates, such as those of Canberra. Flowering occurs around 5 to 8 years from seed. Plants can be pruned hard, and do best on a sandy slightly acid soil of pH 5.5–6.5. They can be vulnerable to borers. Seeds do not require any treatment, and take 32 to 40 days to germinate. B. dentata was introduced into the United Kingdom in 1822.

Where it grows

Across northern Australia, Banksia dentata has been recorded as far west as the Wunaamin Miliwundi Ranges in the western Kimberley through the Northern Territory and extending south to Nitmiluk Gorge and into Queensland, where it is found on the Cape York Peninsula to as far south as Cooktown. Off the coast, it has been recorded from Groote Eylandt and the Wessel Islands, as well as Melville and Bathurst Islands. It also extends onto the Aru Islands, where it is found around Trangan, and New Guinea, where it ranges in the south from Merauke east to Port Moresby, and around Bulolo and Mount Mau. It is the only Banksia species not endemic to Australia. As much of its range is in remote and poorly surveyed country, it is possible that it is found more widely than has been recorded. Pollen samples indicate it has been present on the Torres Strait Islands over the past 8,000 years, though it has not been a prominent component of the island flora.

Uses

Banksia dentata is used as a nectar source in the honey bee industry. Aboriginal people in the Northern Territory would light old seed cones and use them as firebrands, these lasting for up to two hours. The nectar was consumed by indigenous people. A hot smoking flower spike was used to cauterise leprosy sores, and people suffering from diarrhea would squat over smoking cones in the hope this would relieve their symptoms. The thin woody spikes that did not develop follicles were used as nasal ornaments by aboriginal women, and flower spikes were used as combs.

Other Banksia plants

Banksia acanthopoda · Prickly Banksia · Banksia acuminata · Wallum Banksia · Banksia alliacea · Cactus Dryandra · Northern Banksia · Yilgarn Dryandra · Banksia archaeocarpa · Banksia arctotidis · Banksia armata var. armata · Banksia armata var. ignicida