Also known as the Fox Banksia, the Round-fruit Banksia is a tree or shrub species that belongs to the genus Banksia. It is found in the south-west of Western Australia in sandy soil. It was first described by Robert Brown in 1810.
The Round-fruit Banksia varies in flower, leaf, and plant size across its range. There are currently 5 varieties of Round-fruit Banksias recognised. It is usually found as a shrub that is less than 2 metres tall. The plants found in the northern part of the range are larger than those found in the south-east of the range. The maximum it is known to reach is 4 metres. All Round-fruit Banksia varieties have a lignotuber and a root crown. When there is a bushfire, the plant will re-sprout from this swollen and starchy root crown. When new stems grow, they are hairy but become smooth as they mature. Its leaves are stiff, narrow, and linear. They measure between 2.5 – 10 cm long and are on a petiole which are 2-3 mm long. Leaves are generally 1 mm wide and have a pointed tip. Their foliage is generally green, but those belonging to the dolichostyla and caesia varieties have pale blue-grey foliage.
The flower spikes (inflorescences) are usually spherical and are 5 to 8 cm in diameter. However, the larger forms such as those belonging to the dolichostyla variety have a more oval-shaped inflorescence. They flower in the first half of the year, and its blooms are either orange, brown, or yellow in colour. They will take 5-8 weeks to develop from the bud to the finish of the flowering. The flowers have a strong musky smell when they open. These flowers produce unusually large amounts of nectar – so much so that it can actually drip to the grown. When the old flowers fade, they remain curled around the flower spike. Up to 60 follicles will develop on the inflorescences. These follicles are finely furred at first before they become golden brown in colour. Round-fruit Banksias in the Nannup, Jarrah Forest, and Whicher Range areas have larger follicles.
None of the Round-fruit Banksias are commonly seen in cultivation. On Australia’s east coast, it is difficult to grow because the weather is wetter. Grafting trials have been done, but the results have been quite poor. However, they will adapt well to any park or garden that has good drainage, sandy soils, and sunny climates similar to a Mediterranean climate. They are also tolerant of frost. On the plus side, they are good at attracting birds. They also flower when not much else is blooming. Their seeds do not require any special treatment before they are sowed. They will take between 20 – 48 days to germinate.