All Internal Secretory Structures

• Oil cells are specialized cells that accumulate and store essential oils within the plant tissue.
• The oils stored in oil cells play roles in defense against herbivores and pathogens, attraction of pollinators, and plant metabolism.
• Oil cells vary more by the type of oil they store and their plant species than by distinct structural categories.
• Mucilage cells are specialized cells that produce and store mucilage, a gelatinous substance.
• Mucilage cells are located throughout the plant, including leaves, stems, roots, and seeds.
• Mucilage serves several functions such as water storage, seed germination facilitation, and protection against pathogens.
• While mucilage cells are broadly similar, they can be classified based on their location and the specific composition of the mucilage they produce.
• Oil cells are commonly found in the leaves, stems, and flowers of aromatic plants.
• Tannin cells are cells that accumulate tannins, polyphenolic compounds with astringent properties.
• Tannin cells are present in various plant parts, including leaves, bark, wood, fruit, and seeds.
• Tannins play a critical role in plant defense against herbivores and pathogens and in reducing plant tissue decomposition.
• Types of tannin cells are distinguished by the specific tannins they store and their distribution within different plant tissues.
• Resin ducts are specialized tubular structures within plants that transport and store resin.
• Resin ducts are found in the stems, roots, and leaves of coniferous and some angiosperm species.
• Resins produced by these ducts are used for defense against herbivores and pathogens, wound sealing, and sometimes as attractants for pollinators.
• Resin ducts can be classified as primary (developing early in tissue differentiation) or secondary (forming after injury or in older tissues).
• Kino veins are specialized structures in some plants that exude a reddish or dark gum known as kino when the plant is injured.
• Kino veins are primarily found in the bark and heartwood of certain trees, such as eucalypts.
• The kino gum serves protective functions, helping to seal wounds and deter herbivores and pathogens.
• Kino production and vein structure can vary significantly among species, with some producing it as a response to injury and others as part of their normal physiological processes.
• Laticifers are specialized cells or tubes in plants that produce and contain latex, a milky fluid.
• Laticifers are distributed throughout various plant parts, including stems, leaves, and roots, in latex-producing species such as rubber trees, poppies, and figs.
• Latex serves multiple purposes, including defense against herbivores and pathogens, wound healing, and in some cases, commercial exploitation (e.g., natural rubber).
• There are two main types of laticifers: articulated (composed of a series of cells) and non-articulated (a single, continuous cell or tube).