Flowers occur in a typical Banksia flower spike, an inflorescence made up of hundreds of small individual flowers, or florets, densely packed around a cylindrical axis. B. prionotes has cream-coloured flowers with a bright orange limb that is not revealed until the flower fully opens. Known as anthesis, this process sweeps through the inflorescence from bottom to top over a period of days, creating the effect of a cream inflorescence that progressively turns bright orange. The old flower parts fall away after flowering finishes, revealing the axis, which may bear up to 60 embedded follicles. Oval or oblong in shape and initially covered in fine hairs, these follicles are from 14 to 20 mm (1⁄2 to 3⁄4 in) long and 6–11 mm (1⁄4–3⁄8 in) wide, and protrude 3–6 mm (1⁄8–1⁄4 in) from the cone. Inside, they bear two seeds separated by a brownish woody seed separator. The matte blackish seeds are wedge-shaped (cuneate) and measure 8–10 mm (3⁄8–3⁄8 in) long by 5–6 mm (1⁄4–1⁄4 in) wide with a membranous 'wing'.[3][4]