A pome is a type of fleshy fruit produced by flowering plants, particularly those belonging to the Malinae subtribe of the rose family, Rosaceae. This category includes some of the most familiar and widely consumed fruits globally, yet their underlying botanical structure is often misunderstood. The defining characteristic of a pome is that the juicy, edible portion we enjoy is not derived solely from the plant’s ovary, making it distinct from many other fruit types. Understanding the anatomy of a pome reveals a fascinating interaction between the flower’s reproductive and supportive tissues.
The Unique Botanical Structure
A pome is botanically classified as an accessory fruit because a significant part of the mature fruit is formed from tissues outside the ovary wall. In the case of the pome, the bulk of the fleshy, palatable tissue originates from the hypanthium, which is the fused floral tube or receptacle surrounding the ovary. This swollen structure merges with the ovary wall during development, creating the large, succulent body of the fruit.
The structure is clearly divided into three layers, which are derived from two separate parts of the flower. The outermost layer is the skin, or exocarp, which protects the fruit. Beneath this is the thick, edible flesh, which is primarily the enlarged hypanthium and is often referred to as the mesocarp.
The true fruit, which is what develops from the plant’s ovary, is confined to the central core structure. This core is protected by the endocarp, a tough, leathery, or papery casing that surrounds the seeds.
How Pomes Form
The formation of a pome begins with a flower that has an inferior ovary, meaning the ovary is situated below the attachment point of the sepals, petals, and stamens. These outer floral parts, along with the receptacle, fuse together to form the cup-like hypanthium that surrounds the ovary.
Following successful pollination and fertilization, the ovary wall begins to mature into the core, while the surrounding hypanthium tissue is simultaneously stimulated to grow and swell. These two parts, the true fruit (ovary) and the accessory tissue (hypanthium), develop in a tightly fused manner. The remains of the sepals and stamens from the original flower can often still be seen as shriveled remnants at the end of the mature fruit opposite the stem.
This fusion explains why the seeds are completely enclosed within the core, and why the majority of the food storage tissue comes from the floral base. This developmental path distinguishes pomes from simple fruits like berries, where the entire edible portion comes only from the ripened ovary.
Common Examples of Pomes
The pome classification includes a variety of familiar fruits that share this unique structure. Apples and pears are the most widely recognized examples, both belonging to the Malinae subtribe. Within this group, structural variations exist; for instance, the gritty texture often found in pears is due to the presence of stone cells, or sclereids, scattered throughout the fleshy hypanthium.
Quinces are another common pome, often recognizable by their lumpy shape and requiring cooking before consumption due to their high acidity and firm flesh. Less globally common but still classified as pomes are fruits like loquats and medlars. Even some smaller, berry-like fruits, such as chokeberries and serviceberries, are technically pomes because their flesh is also derived from the hypanthium surrounding the central core.