Banksia caleyi, commonly known as the red lantern banksia or Caley's banksia, is a species of woody shrub of the family Proteaceae native to Western Australia. It generally grows as a dense shrub up to 2 m (7 ft) tall, has serrated leaves and unusual red, pendent (hanging) inflorescences which are generally hidden in the foliage. First described by Scottish naturalist Robert Brown in 1830, Banksia caleyi was named in honour of the English botanist George Caley. No subspecies are recognised. It is one of three or four related species with hanging inflorescences, which is an unusual feature within the genus.
Found south and east of the Stirling Ranges through to the vicinity of Jerramungup, Banksia caleyi grows in a habitat burnt by periodic bushfires. Plants are killed by fire and regenerate by seed afterwards. The species is classified as Not Threatened under the Wildlife Conservation Act of Western Australia. In contrast to other Western Australian banksias, it appears to have some resistance to dieback from the soil-borne water mould Phytophthora cinnamomi, and is comparatively easy to grow in cultivation.
Banksia caleyi grows as a many-branched bushy shrub to 2 m (7 ft) in height, with crumbly grey bark. Rarely, plants of up to 4 m (13 ft) have been found. The new growth is hairy, and generally occurs in summer. The branchlets become smooth after around two years. The stiff leaves are narrowly wedge-shaped (cuneate) and measure 5–14 cm (2–5 1⁄2 in) in length by 1.3–2.4 cm (1⁄2–1 in) wide. The leaf margins are serrated, with many teeth measuring 0.4–0.6 cm (1⁄8–1⁄4 in) each.
Flowering takes place between September and January. The inflorescences hang down from the ends of three- to five-year-old branchlets deep within the shrub and measure 5–9 cm (2–3 1⁄2 in) in length and roughly 7 cm (2 3⁄4 in) in diameter. The flowers are cream at the base and deep pink to red in the upper half, and are brightest before anthesis and then gradually fade with age. The inflorescences eventually turn grey, the old flowers remaining as up to 25 large woody follicles develop. Oval in shape and covered with fine hair, the follicles can reach 4 cm (1 5⁄8 in) long, 2.5 cm (1 in) high, and 2.5 cm (1 in) wide.
The obovate seed is 4.3–4.7 cm (1 3⁄4–1 7⁄8 in) long and fairly flattened, and is composed of the wedge-shaped seed body proper, measuring 1.4–1.5 cm (1⁄2–5⁄8 in) long and 1.6–1.7 cm ( 5⁄8 in) wide, and a papery wing. One side, termed the outer surface, is dark brown and wrinkled, while the other is black and smooth. Both surfaces sparkle slightly. The seeds are separated by a sturdy dark brown seed separator that is roughly the same shape as the seeds with a depression where the seed body sits adjacent to it in the follicle. Seedlings have cuneate cotyledons which measure 1.1–1.3 cm (3⁄8–1⁄2 in) long and 1.3–1.4 cm ( 1⁄2 in) wide. These are dull green with three veins, and the margin of the wedge may be red and crenulated (lined with small teeth). The hypocotyl is red and measures 1.5–2 cm (5⁄8–3⁄4 in) high. Seedlings have hairy stems and leaves that are oppositely arranged (arising from the stem in pairs) that are obovate with triangular-lobed serrate margins.