Synonyms: Banksia conchifera, Banksia mitis, Banksia serrata var. hirsuta, Banksia serrata var. serrata, Banksia serratifolia, Banksia serrifolia, Banksia undulata, Isostylis serrata, Sirmuellera serrata, Sirmuellera serratifolia
Banksia serrata, commonly known as old man banksia, saw banksia, saw-tooth banksia and red honeysuckle, is a species of woody shrub or tree of the genus Banksia in the family Proteaceae.
It is one of the four original Banksia species collected by Sir Joseph Banks in 1770, and one of four species published in 1782 as part of Carolus Linnaeus the Younger's original description of the genus. There are no recognised varieties, although it is closely related to Banksia aemula. It grows exclusively in sandy soils, and is usually the dominant plant in scrubland or low woodland. Banksia serrata is pollinated by and provides food for a wide array of vertebrate and invertebrate animals in the autumn and winter months. It is an important source of food for honeyeaters. It is a common plant of parks and gardens.
Banksia serrata usually grows as a gnarled and misshapen tree up to 15 m (50 ft) tall, although in some coastal habitats it grows as a shrub of 1–3 m (3–10 ft), and on exposed coastal cliffs it has even been recorded as a prostrate shrub. As a tree, it usually has a single, stout trunk with the rough grey bark characteristic of Banksia. Trunks are often black from past bushfires, and ooze a red sap when injured. The leaves are dark glossy green above and light green below, 8 to 20 centimetres (3 to 8 in) long, and 2 to 4 centimetres (0.8 to 2 in) wide. Except near the base of the leaf, the margins are serrated with lobes between 1 and 3 millimetres (0.04 and 0.1 in) deep. Leaves occur crowded together at the upper end of branches, giving the canopy a thin, sparse appearance. The flowers are a silvery grey colour, with cream or golden styles, and occur in Banksia's distinctive cylindrical flower spikes. "Cones" may have up to 30 follicles, and usually appear hairy due to the retention of old withered flower parts.