Flowers occur in typical "Banksia" "flower spikes", inflorescences made up of hundreds of pairs of flowers densely packed in a spiral around a woody axis. "B. brownii"'s flower spike is a metallic red-brown colour, roughly cylindrical, 6 to 19 centimetres (2–7½ in) high and eight to ten centimetres (3–4 in) wide. Each flower consists of a tubular perianth made up of four united tepals, and one long wiry style. Perianths are cream at the base and grey-brown at the end. Styles are rusty red-brown with a cream tip, and downwardly hooked rather than straight. The style end is initially trapped inside the upper perianth parts, but breaks free at anthesis.