Covering seed is a term used to describe the process of protecting and nurturing a seed until it is ready to be planted. SESAME (6 letters) is a type of seed that is often used in cooking and baking, and is also used to make oil. An ARIL (4 letters) is a fleshy covering that surrounds some seeds, such as those of the yew tree. An OVULE (5 letters) is a structure found in plants that contains an embryo and eventually develops into a seed. All three terms are related to the process of covering seed, and are important components of the process.