The leaves of Leucadendron sessile are narrowly elliptic with entire margins and pointed tips. The flat blades are hairless, varying in colour from bluish green to yellow-green.
The involucral leaves below the bracts of the flowerheads are bright yellow or red. They do not first become pale before assuming their floral colouring but sometimes display conspicuous vein lines.
Above the full length involucral leaves there is a conspicuous collar of short bracts that turns brown early (Manning, 2007; Bond and Goldblatt, 1984; iNaturalist).