Lignin is a dense, hard, waterproof material. Secondary walls are always deposited inside primary walls. Cell walls may also be impregnated with waxy, waterproof compounds such as cutin or suberin . Plant cells typically contain one or more of the many types of plastids . The most familiar type is the chloroplast, but the same organelle can contain various pigments and other substances, and can fulfill a range of functions.
Chromoplasts contain red or yellow xanthophyll pigments in large amounts.
They occur in flower petals and other pigmented structures. Leucoplasts are nonpigmented plastids, which usually occur in the epidermis. Amylopasts have little pigment but contain starch grains. They are found in areas of food storage, such as roots. Note that pigments often occur outside of plastids, either dissolved in the vacuole in the case of anthocyanin pigments or as solid pigment bodies suspended in the cytoplasm.