Ceramide is an important component of the sphingolipids in many eukaryotic species with the important exception of mammals. The lipid components of the ceramide phosphatidylinositol of the few plant species to have been studied are mainly saturated, with primarily phytosphingosine as the long-chain base and tetracosanoic acid (24:0) as the fatty acid component. Ceramide phosphatidylinositol per se tends to contain a wider range of lipid constituents.