Tomatoes (Solanum lycopersicum) come in a wide array of shapes, sizes and colors with thousands of heirloom and hybrid varieties from which to choose. Tomatoes grow equally well in the garden, containers and even upside down in hanging baskets, and they generally fruit within 45 to 90 days of planting. High in antioxidants, such as lycopene, and vitamins A and C, tomatoes provide intense flavor and nutrition to any meal.
The flesh and seeds of tomatoes are protected by outer skin, known as epidermis. During the early stages of development, the skin is taut and resistant to damage. As the fruit ripens, the skin stretches and softens. The skin is edible and typically only removed when making sauces or preserves.
The outer flesh of the tomato is called the pericarp wall. This solid portion of the tomato contains a vascular bundle that runs from the stem through the outer perimeter inward to the seeds, delivering moisture and nutrients. The inner portions of flesh dividing the locular cavities are known individually as septum or septa in plural form. The flesh of the pericarp wall and septa, referred to as the meat, are the main portion of the fruit used in cooking after skin and seeds have been removed.
Depending on the variety of tomato, it is either bilocular or multilocular. Bilocular fruits have two main locular cavities divided by one septum. Multilocular fruits contain three or more cavities divided by several septa. The septa join at the columella, or center point, of the tomato. This portion of the tomato holds the least flavor and is usually removed during preparation.
The reproductive system of the tomato includes the placenta and seeds, protected by a gelatinous membrane. Each seed is attached to an individual vessel within the vascular bundle. The placenta tissue also contributes to the meat. Seeds and membranes can be left in or removed, depending on personal preference and recipe.