Hooker's banksia

Description

Banksia hookeriana, commonly known as Hooker's banksia, is a species of shrub of the genus Banksia in the family Proteaceae. It is native to the southwest of Western Australia and can reach up to 4 m (13 ft) high and 3 m (9.8 ft) wide. This species has long narrow serrated leaves and large, bright flower spikes, initially white before opening to a bright orange that appear over the cooler months. The flowers are pollinated by honeyeaters. The ageing flower spikes develop woody seed pods known as follicles. B. hookeriana is serotinous — large numbers of seeds are stored in the plant canopy for years until the plants are burnt by bushfire. Banksia hookeriana grows as an bushy shrub to around 3 metres (10 ft) in diameter, and 3–4 metres (10–13 ft) high. It has smooth bark. New growth appears in spring and summer. Anywhere up to several hairy 15–25 centimetres (6–10 in)-long branchlets arise from just below nodes on larger branches. The leaves themselves are scattered along the branchlets but more crowded toward the tips. They are 6–16 centimetres (2+1⁄4–6+1⁄4 in) long and 0.5–1.2 centimetres (1⁄4–1⁄2 in) wide, and slightly concave in shape. The leaf margins have 20–45 triangular lobes long each side. The v-shaped lobes are 1–3 mm high by 1–6 mm wide. The flower spikes, known as inflorescences, arise at the ends of branchlets, appearing from late April to October, with a peak over July and August. They are 9–10 centimetres (3+1⁄2–4 in) wide and 7–12 centimetres (2+3⁄4–4+3⁄4 in) high. Each flower spike contains around 1000 individual small flowers. The flowers remain on the ageing spikes, which go on develop up to 20 woody seed pods (follicles) each. It occurs on sandplain shrubland between Arrowsmith and Eneabba and specifically on the Gingin scarp and Dandaragan plateau in Western Australia, found on flat or gently sloping land. It grows on deep white or yellow sand, and tends to be the dominant species. Commonly grows with Banksia attenuata, B. elegans and Eucalyptus todtiana. Banksia hookeriana is highly regarded in the cut flower industry, and has markets both in and outside Australia. Cut flowers have a vase life of ten days. A fast-growing plant in cultivation, B. hookeriana flowers 3–4 years from seed. It requires good drainage. It can be grown in Mediterranean climates such as Victoria and South Australia, but does not tolerate climates with summer humidity. Seeds do not require any treatment, and take 23 to 49 days to germinate.