Woody flowering plants are perennial, that is, they continue to grow and reproduce for many years.
They have one or more permanent stems above ground, and numerous smaller branches. The stems and branches have a strong woody core that supports the plant and contains vascular tissue for transporting water and nutrients. Outside the woody core is a layer of tough, protective bark, which has lenticels (tiny pores) in it to enable gases to pass through. Woody flowering plants may be shrubs, which have several stems arising from the soil; bushes, which are shrubs with dense branching and foliage; or trees, which typically have a single upright stem (the trunk) that bears branches. Deciduous woody plants (e.g., roses) shed all their leaves once a year and remain leafless during winter. Evergreen woody plants (e.g., ivy) shed their leaves gradually, so retaining full leaf cover throughout the year.
