Do you know which part of the plants you eat as vegetables is actually being consumed?
Once you realize which part of the plant you're eating, don't you start wondering what happens to the parts you don't eat? What kind of plant that vegetable comes from?
The plants we see as vegetables on our plates or displayed in stores—the form they show us in those moments is just one scene, one small part of the vegetable plants' story.
This is a story about getting a little closer to that form, looking a bit more closely than usual, and enjoying vegetables and plants.
The Various Parts of Plants
The human body has various parts like the head, arms, legs, torso, and internal organs inside. Fish have fins and scales, birds have wings and beaks—all living creatures possess diverse parts unique to them. Plants, as living organisms, are no exception and also possess various parts. What parts do plants have? When we think of plants, the most typical parts that come to mind are the “grass,” and of course, the most commonly seen part: the ‘leaf,’ meaning the leafy part. Then there's the ‘flower,’ which highlights their beauty, and the ‘fruit,’ which also provides deliciousness. Furthermore, perhaps not something we notice often, but the very foundation that keeps the plant rooted in place: the ‘root,’ the root system. So, what parts do plants have?
Leaf
The majority of the parts we commonly see on plants are probably these ‘leaves’. It makes sense they're the majority, since leaves are the parts that grow above the soil. For aquatic plants like lotus or water hyacinth, you could say they grow above the water. This is why leaves are the parts most often seen by human eyes. Also, during growth, they show us their shape for a relatively long time compared to other parts.
In appearance, some are flat and oval-shaped, some are long and pointed, some are jagged or rough, and some have thin hairs growing on them. Most are green in color. Because of this, places where plants grow vigorously, such as forests, fields, farms, and gardens, are often described or named as “green XX.” However, some leaves are purple, red, yellow, or even mixed with patterns of these colors. In autumn, we can also see leaves that have fallen to the ground in the form of “fallen leaves.”
The roles of these leaves include photosynthesis, respiration, and transpiration. In photosynthesis, leaves absorb light, take in carbon dioxide from the atmosphere, and release oxygen. At the same time, they use the carbon from the carbon dioxide to produce their own nutrients. These nutrients are sugars. They mainly become glucose, which is the basis of starch. They use these nutrients to make their bodies stronger and as a source of life activities, including respiration. These nutrients, expressed as sugars, contribute sweetness to vegetables, provide stickiness like starch, and contribute to texture as dietary fiber.
Leaves are hybrid parts that combine functions akin to the human mouth, nose, lungs, stomach, and other digestive organs, along with an energy supply system like solar panels.
stem
Stem
The stem primarily supports the plant body while serving as a main transportation route, distributing nutrients produced by photosynthesis in the leaves and water and nutrients absorbed by the roots throughout the entire plant. True to this role, the stem acts as a relay point for the entire plant body, connecting the leaves above ground to the roots below. The term “stem” is primarily used for herbaceous plants like flowers and many vegetables. In woody plants like trees, which have hard, sturdy, lignified stems, the term “trunk” is used. Both ‘stem’ and “trunk” refer to the same part of the plant performing the same function.
Visually, it occupies a position akin to the main body of the plant. While flowers and leaves may fall off during seasonal changes or when water is scarce and the plant dries out, the stem remains until the very end. For these reasons, it can be considered the plant's main body.
The stem functions like the spine in humans, encompassing the torso along with major vessels like the aorta and vena cava. Furthermore, by shedding leaves in response to water availability or season, it seems to control the plant's water balance. This suggests a regulatory function, evoking the image of a central nervous system controller like the brain or spinal cord.
Flowers
Flowers, the very symbol that colors this world. They are the parts of plants that bloom in vibrant colors when the plant body reaches maturity or during its maturation period. Most are seen for ornamental purposes rather than as food. Edible varieties are often consumed at the bud stage before full bloom, though edible flowers do exist and are categorized as such.
Flowers come in a vast array of hues and fragrances.
Even within the same plant species, some produce flowers of different colors. Regarding flower coloration, it is said that plants developed diverse shades to make their location more visible to pollinating insects—such as honeybees and swallowtails—that come to sip nectar. Insects like honeybees perceive color differently than humans, so they might detect and explore hues that are hard for us to discern. Additionally, some plants, like hydrangeas, change color depending on whether the soil leans acidic or alkaline—essentially, based on the level of hydrogen ion concentration.
Some flowers emit pleasant scents that relax people, while others give off unpleasant odors, including the smell of decay. Of course, how people perceive each flower's scent varies greatly due to individual preferences, so it's impossible to generalize about any particular flower's fragrance. Why such diversity in scent? It's also said to be for attracting beneficial insects to the plant. There are flowers said to emit a scent reminiscent of toilet odors, which humans generally find unpleasant. This is the Rafflesia. While its name might remind many of a certain Pokémon character, it's also called the world's largest flower and the world's smelliest flower (fitting for the final evolution of Stinkweed, right?). For the Rafflesia, the beneficial pollinating insects are flies. Therefore, it is said to emit a scent resembling the putrid odor that flies, with their strong preference for decay, find appealing.
As for such ‘flowers’, the reason they attract beneficial insects to the plant that produces them is to have them carry pollen, meaning to assist with pollination. Such flowers possess stamens (bearing pollen) and pistils, along with nectar. Insects come to collect this nectar and pollen. In doing so, their bodies come into contact with the flower, allowing pollen from the stamens to adhere to them. This pollen is then transferred to the pistils, leading to pollination.
Additionally, some plants lack what we typically envision as a ‘flower’. Examples include gymnosperms and grasses. While they don't possess the colorful, fragrant blooms most people associate with flowers, they do have the essential ‘flower’ component. These plants do not rely on visiting insects for pollination. Instead, they utilize wind for pollination, hence the term “wind-pollinated flowers.” Since they no longer depend on insects, they are said to have lost the need for flashy, showy flowers.
As can be deduced from these points, the ‘flower’ can be considered the reproductive organ of plants as living organisms.
root
Roots serve as the foundation supporting the entire plant body, primarily spreading underground beneath the soil. Because they are not the part of the plant we usually see, they may seem like an unknown world to those who don't interact with plants often.
Furthermore, the role of the ‘roots’ is to absorb water and nutrients from the soil and deliver them throughout the entire plant body. The difference between the nutrients produced by the ‘leaves’ and the nutrients absorbed by the ‘roots’ lies in their form: the nutrients from the leaves are sugars, meaning organic matter, while the nutrients absorbed by the roots are inorganic nutrients containing minerals. To draw an analogy with human diets, the nutrients from the ‘leaves’ might be likened to staple foods like rice and other carbohydrates, while the nutrients from the ‘roots’ could be seen as side dishes like meat, fish, salads, pickles, soups, or even supplements and protein powders. This is purely an analogy, of course. Both types of nutrients are essential for life processes and building the body.
While roots are fundamentally found underground, there are also “adventitious roots” that develop from nodes on above-ground stems. Some roots enlarge to store water and nutrients, and many of these are edible. Furthermore, some structures that appear to be roots are actually stems, like rhizomes, making visual distinction quite challenging.
Among the minerals in the soil, cations like potassium, calcium, and magnesium typically adhere to soil particles. However, as roots breathe, they trigger a process that detaches these minerals, making them easier for the plant to absorb as nutrients.
Such roots are sometimes described as the plant's equivalent of the small intestine in the human body. In other words, they perform a function similar to the part responsible for digestion and nutrient absorption. Similar to the recent focus on gut microbiota, the “rhizosphere”—the soil space surrounding plant roots—is also said to contain diverse microorganisms and bacteria that contribute to plant growth and development. The ‘root,’ a part that performs a function akin to the small intestine, may indeed be the plant's symbolic component, even if it's not something we typically notice.
Which part of this vegetable?
First, I briefly described some parts of vegetables and plants. Plant bodies have various parts, each serving different purposes. We'll now look at exactly which parts of these plant bodies we typically eat as vegetables, examining specific vegetables alongside them.
This time, we'll focus on the 15 vegetables designated as “specified vegetables” within Japan, exploring where each vegetable comes from within the plant body.
What are designated vegetables?
Have you heard of the term “designated vegetables”? Designated vegetables refer to vegetables selected as particularly important within Japan by the Ministry of Agriculture, Forestry and Fisheries. Their importance lies in ensuring stable production and supply of vegetables essential to the nation's dietary habits. From another perspective, they are the most representative, commonly seen, and frequently consumed vegetables—the super-major vegetables, so to speak. With broccoli, which has been tentatively decided to be added starting in fiscal year 2026, the total number of items will be 15 as listed below.
- Cabbage
- Spinach
- Lettuce
- Green onion
- Onion
- Chinese cabbage
- Broccoli
- Cucumber
- Eggplant
- Tomato
- Bell pepper
- Daikon radish
- Carrot
- Taro
- Potato
Let's take a look at which parts of these designated vegetables you usually eat.
１．Cabbage
葉肉（ようにく）
Shredded cabbage, stir-fried vegetables, cabbage rolls, and even the addictive cabbage at yakiniku restaurants—where exactly do we usually eat these parts? This might be a relatively straightforward question. It's the leaves—yes, the ‘leaf’. And the green part of the leaf is called the ‘leaf blade’. Sometimes, like with purple cabbage, you see leaf flesh that's mainly purple instead of green. At the center of the leaf is a white part often called the “core,” which looks like it's covered in a white net-like pattern. This “core” part has strong fibers, so it's often removed during cooking. The net-like part extending from it also has a fibrous texture that provides a noticeable bite, though not as much as the core itself, compared to the green parts. This net-like section starting from the core is called the ‘leaf veins’. Within these ‘leaf veins’, the core itself is called the ‘midrib’, and the net-like sections branching out from it, gradually becoming thinner, are called the ‘side veins’.
leaf veins
Leaf veins are the thread-like or net-like patterns found on leaves. This part acts as a pathway for circulating water and nutrients drawn up from the roots throughout the leaf, and for transporting nutrients produced by photosynthesis in the leaf outwards. In other words, this constitutes the “vascular bundle” within the leaf. Focusing specifically on the ‘leaf’ section, it serves as the transit route for nutrients and water originating from the roots, their destination point, and the departure point for nutrients produced within the leaf. Essentially, you can think of it as a terminal-like existence. Furthermore, these leaf veins are the stringy parts you feel when eating the leaf as food. Feeling stringy means it's tough to bite through, indicating the fibers are strong and firm. True to this, within the leaf's structure, it is a sufficiently hard part, serving as the foundational framework, or the skeletal structure, of the ‘leaf’. You might imagine a tunnel-like structure with concrete heavily layered and stacked.
While the role of leaf veins is as described above, don't you think they also contribute to the leaf's visual appeal? That is, they appear like a “pattern” on the leaf, which is why we perceive them this way. A craft that utilizes this design is the “leaf vein specimen.” It's a work that highlights the stringy firmness and the pattern formed by the veins as they run through the leaf. It's one way to interact with leaves beyond eating them.
Main artery
The thickest line within the leaf veins is called the ‘midrib’. While multiple veins of equal thickness may sometimes be present, the thickest line is often found running down the center of the leaf, much like the “core” seen in cabbage leaves. This pattern is observed in many plant species. This central line is also referred to as the “central vein”.
lateral vein
The lines branching off from the main vein are called ‘lateral veins’. After branching off from the main vein, lateral veins branch again, and then branch again, spreading out to form a net-like pattern. The first lateral vein branching from the midrib is called the “primary lateral vein,” and subsequent branches are numbered as “secondary lateral veins.” However, when considering the veins as individual lines rather than branches, the midrib itself is counted as the “primary vein,” and the primary lateral veins are counted as “secondary veins.”
In cabbage ‘leaves’, the ‘core’ part was the ‘main vein’ of the ‘veins’. The ‘veins’ serve as the framework, essentially the bones physically supporting the ‘leaf’ unit. Regarding the ‘veins’, especially the ‘main vein’, some might have thought it was the ‘stem’. Looking solely at their function, it makes sense they perform nearly identical roles, and consequently, their structure and shape appear similar. So, does the cabbage we usually eat have a stem? Of course it does. Where exactly? In its round, spherical state, it's only visible from the bottom end. The bottom end is the opposite side from where the leaf edges overlap, specifically the thicker side of the leaves, or to be precise, the thicker side of the “main vein.” That area, the cut surface, the round part where the main vein connects—that is the cabbage's ‘stem’. While it's only visible from that angle when the cabbage is spherical, cutting it vertically in half reveals the stem's cross-section clearly. It presents a cross-section shape that could be called pencil-like, or perhaps triangular with a pointed tip, serving as the foundation from which the leaves grow. This is the cabbage's ‘stem’. You might casually notice it while cooking. However, this part, being close to the main vein and even more fibrous in texture, is often referred to as the ‘core’ and discarded, much like the main vein. Of course, depending on the cooking method, it can be quite delicious. Personally, I find it tasty when pickled in miso.
2. Spinach
Deep green in color, spinach is packed with nutrients—so much so that it could be called one of the original superfoods, as seen in its role as a power-up item in the American cartoon “Popeye.” It carries such a strong image of high nutritional value that people might think, “Spinach = eating your vegetables properly.” The representative nutrient in its rich nutritional profile is iron. Iron plays a vital role in humans by transporting oxygen throughout the entire body. Spinach is famous among vegetables for its high iron content. Furthermore, it's also rich in vitamin C, which acts as a necessary supporter for the absorption of that iron—meaning it helps the body effectively utilize the iron obtained from spinach during growth and metabolism. In other words, eating spinach aligns with the idea of supplying iron more effectively to the body, which is likely why it carries that “nutrient-packed” reputation.
But what part of this vegetable do we actually eat? As you know, the main edible part of spinach is the ‘leaf’. This includes the leaf blade itself, plus the stem-like extension along the central vein. This part is called the petiole, and it's also considered part of the leaf. Also, those who eat spinach frequently might be consuming its ‘roots’ too. If you choose pre-cut spinach, especially frozen varieties, the ‘roots’ are often removed, so you might rarely see them. Those who often eat fresh spinach might be consuming a very small amount of the ‘stem’ as well. The reason I say “might be eating” is that the ‘stem’ portion, in the plant state typically consumed as spinach, is extremely small. The ‘petiole’, which could be mistaken for a stem, is classified as part of the leaf. Therefore, the ‘stem’ and ‘root’ of spinach are essentially rare parts. Their flavor profile also holds a deeper sweetness than the leaf flesh, combined with a subtle earthy aroma. Depending on how you perceive it, they might even be considered a rare delicacy.
petiole
The leaf veins, primarily the extension of the midrib and central vein, connect to the stem at this point. The leaf blade and veins, excluding the petiole, are collectively called the ‘leaf blade’. The structure of a ‘leaf’ consists of three parts: the ‘leaf blade’, ‘petiole’, and ‘stipule’. (A ‘stipule’ is a small leaf-like structure found in some plants at the junction between the petiole and the stem.) The role of the ‘petiole’ is to support the ‘leaf blade’ and, as evident from its position along the extension of the leaf veins, it serves as a pathway for water and nutrients drawn up from the roots, as well as nutrients produced by the leaf's photosynthesis. Because the petiole also forms the skeletal structure supporting the leaf blade, it has relatively strong fibrous tissue. Consequently, vegetables like spinach, where the petiole is eaten, can sometimes have overly tough fibers that result in a poor texture or mouthfeel, depending on the growth stage at harvest or the freshness level.
3. Lettuce
Lettuce is one of the staple vegetables in salads. While broadly categorized into two main types—the more commonly imagined round lettuce, known as “head lettuce,” and the non-round “leaf lettuce”—there are actually many diverse varieties of lettuce. Of course, the edible part is the ‘leaf’. Like cabbage, you can see the finer parts. Even within lettuce, the color and shape of the leaves vary greatly. You might find that a salad packed with all sorts of leaves is actually mostly lettuce. In terms of taste, its texture stands out first—it's crisp and bursting with freshness. It also has a subtle bitterness, or a stronger bitterness depending on the variety, making it useful for adding accents.
4. Green Onions
It's no exaggeration to call green onions the ultimate condiment. Of course, savoring them as the star ingredient in negiyaki pancakes is another delightful luxury. While green onions are versatile, edible varieties are generally divided into two main types: “naga-negi” (long green onions) and ‘aonegi’ (scallions). Some theories suggest “naga-negi” is the primary variety in eastern Japan, while “aonegi” dominates in western Japan. “Long green onions” are also called “white onions” or “root onions,” while “green onions” are sometimes referred to as “leaf onions.” While there are differences in cultivated varieties, the fundamental distinction lies in cultivation methods. If grown directly from seed, they develop like “green onions.” To grow them like “white onions,” cultivation management is required, such as partially burying the leaves in soil to suppress photosynthesis. So, exactly which part of the leek do we eat? It might be a bit harder to tell than with cabbage, spinach, or lettuce. Plus, you might think it differs between “long leeks” and “green onions,” but actually, what we eat in both cases is the ‘leaf’. You might wonder, “But aren't we eating the ‘stems’ of long green onions, while we eat the ‘leaves’ of scallions?” The answer is that you're “very close,” but also “you've been tricked.” That's because the part of the long green onion that looks like a ‘stem’ is actually called a ‘pseudostem’ – literally a “fake stem.” It's actually part of the ‘leaf,’ shaped to wrap around the inner new leaves, and is called a ‘leaf sheath.’ Therefore, both ‘long green onions’ and ‘scallions’ are primarily consumed for their 'leaves.' Once again, “So where is the stem?” The stem of the leek is even thinner and harder to see than in the three leafy vegetables mentioned above. It is located between the ‘leaf’ and, if you look closely, the base of the ‘pseudostem’ and the ‘root’. It is a very small part, so it's worth looking carefully.
Leaf sheath
The leaf sheath is the part that swells to form a protective sheath-like structure for the new leaf (axillary bud) inside. Like the petiole, it serves a skeletal role in supporting the leaf blade and functions as a pathway for transporting water, nutrients, and nutrients. In leeks, the ‘leaf sheath’ is the part extending toward the roots from the point where the green leaf blade appears to attach, at the base where it forms a fork-like structure. In “long green onions,” this is more clearly visible: the white part is the ‘leaf sheath’ section. Therefore, “long green onions” can be considered a product of blanching cultivation, which suppresses sunlight exposure to the leaf sheath portion.
pseudostem
As the leaf sheaths form sequentially from the new leaves (axillary buds), enveloping the inner sheaths and becoming tubular, they rise up with a dignified appearance, much like a ‘stem’. This bundle of leaf sheaths formed in this ‘stem-like’ manner is called a ‘pseudostem’. Similarly, in leeks, rice, bamboo shoots, and others, the cylindrical structure that seems impossible to peel completely is also essentially a pseudostem. While it appears as solid as a stem, it is actually a bundle of leaves.
5. Onion
Thinly sliced raw, thickly cut stir-fried to retain texture, chopped raw in sauces, or cooked as a base for dishes—the onion is an excellent aromatic vegetable. While onions have a thin skin covering a white, endlessly peelable part that is primarily eaten, what exactly is that part? The key phrase is “endlessly peelable.” Yes, it's the same as with green onions. It's the ‘leaf’ called the ‘pseudostem’. Each peelable layer corresponds to one leaf. Though called leaves, these are exceptionally thick and are specifically termed ‘storage leaves’, leaves that store nutrients. Furthermore, this ‘storage leaf’ forms the stem. More accurately, the tightly packed, layered cluster of these storage leaves, which is nearly spherical and also called a bulb, is called the ‘bulb scale’. The actual stem at this stage is the compacted section extending from the base of each ‘bulb scale leaf’ to where the roots emerge. This is the part that remains attached as the base when chopping or slicing onions, the part left behind and discarded. This section, along with the bulbous portion, is called the ‘bulb’. It's a plant where it's very unclear which part you're eating—sometimes called the “stem,” sometimes the ‘root’ like a bulb. However, the main edible part of the onion is the ‘leaf’. Similar to green onions, even within the ‘leaf’, the ‘petiole’ part can transform into a ‘storage leaf’, meaning the ‘leaf blade’ (leaf flesh) part—the green “The Leaf”—is rarely eaten. Since onions are primarily harvested after their leaves have withered and fallen over, you might rarely encounter them this way. However, sometimes you can find “new onions” or, even earlier, “leaf onions,” where you can enjoy the entire ‘leaf’ with its small ‘bulb’ and ‘leaf blade’ attached. If you spot them, it might be your chance!
Storage leaf
This is a part of the ‘leaf’ that has swollen and become fleshy by storing nutrients obtained through photosynthesis. Each layer of an onion is a single leaf that has stored sugars formed from sunlight. The reason cutting an onion makes you cry is certainly not because you're moved by the mystery of nature's bounty stored through photosynthesis from the sun.
Bulb scales (Rinkei-yo)・Bulb scales (Rinkei)
When storage leaves overlap multiple times or densely layer like scales, they are called ‘bulb scales’. As they are leaves, the ‘bulb scales’ connected to the stem at their base are referred to as ‘bulbs’ when viewed as a single unit with the stem at their base. As noted earlier, perhaps because the term ‘stem’ carries connotations of the plant's main body, the section referred to as ‘stem’ is the part formed predominantly by leaves—that is the ‘bulb’. Focusing on the bulb ‘first’ and then on its leaf portion ‘later’ might explain why it's called the ‘bulb leaf’ within the ‘leaf portion of the bulb’.
6. Chinese cabbage
The true delight of hot pot, napa cabbage shines even in pickles. Though rising temperatures have driven up prices lately, what part of this vegetable do we actually eat? If you've read this far, you probably already know—it's the leaves, of course. Like cabbage and lettuce, but more so, the leaf stalks are noticeably thicker and larger, making them a versatile ingredient. You might even find its fibrous texture more palatable than cabbage or lettuce. The ‘petiole’ contains just the right balance of umami and moisture, with fibers running lengthwise along the cabbage (from the base towards the leaf tip). This allows for versatile cooking techniques: slice along the fiber direction to retain texture and shape, or cut perpendicular to the fibers for a tender, melt-in-your-mouth texture. Additionally, when cultivated from cold to warm seasons, it also produces rapeseed flowers, making it a vegetable that can be enjoyed as a seasonal ingredient.
7. Broccoli
Broccoli has been tentatively selected as a designated vegetable for fiscal year 2026. While it's packed with nutrients and boasts a satisfying texture and umami flavor, what part of the broccoli are we actually eating? Its green color might lead some to think we're eating the ‘leaves,’ while others might assume we're eating the stem. Some might even imagine we're eating the whole plant, much like a tree, based on its silhouette. Compared to other vegetables we picture, its edible appearance is so different that it might be hard to imagine a specific part. The main edible part of this broccoli is not the ‘leaves’. It's not that we don't eat the ‘leaves’ at all, but they're rarely eaten. That's because most of the leaves are removed before it reaches store shelves. So where exactly do we eat? When we think of broccoli, we think of that satisfying crunch. While it's not the origin of the name ‘broccoli’, that firm, satisfying texture is definitely one of its key points. That firm texture means it's fibrous, and that means it's the ‘stem’. That tree-trunk-like main body? That part is the stem. So what exactly is that iconic, bomb-shaped head atop the stem? That part will eventually bloom. Each of those deep green, granular buds will open into a flower. In other words, before blooming, each of those granules is a flower bud. The broccoli's bomb-shaped head is a cluster of buds, called a ‘flower head’ (karai). Since flowers are beginning to form inside these buds, depending on how you look at it, eating it is quite similar to eating the ‘flower’ itself. We touched on the concept of ‘flower buds’ (nabana) with Chinese cabbage earlier; the edible part of broccoli shares the same fundamental purpose as those flower buds. Incidentally, depending on growing conditions, a condition called “leafy” can occur where leaves sprout from the gaps between the flower buds. If you encounter such broccoli, you're almost inevitably eating the leaves along with it. That broccoli is primarily eaten for its stems and flower buds.
Flower bud
To put it plainly, it's the “bud.” The part before the flower fully blooms. It's the part that will eventually become the flower—the reproductive organ that leads to pollination and leaves behind seeds. Thinking of it as food, if we shift to a meat-eating image, it might be akin to the hormone-rich parts derived from reproductive organs, like testicles, gonads, or milt. Such a rare cut, taken just before it blooms, just before it reaches its full, beautiful splendor. The subtle fragrance and umami we can sense might stem from capturing—or perhaps harvesting—that miraculous, fleeting moment...
8. Cucumber
Cucumbers you just want to bite into whole, cucumbers used as the main ingredient in pickles and often eaten in salads. What part of this vegetable do we eat? We eat the ‘fruit’. The fruit of the cucumber comes from the female flower. Have you ever seen a cucumber flower? Whether you have or haven't, can you tell if it's a female or male flower? Just looking at the flower itself, meaning the open petals, might make it quite difficult to tell. However, if you keep in mind that “the fruit comes from the female flower” while looking at it, you'll likely find it surprisingly easy to tell at a glance. Why is that? Behind the cucumber's female flower, at the tip of the flower's base, there is a small cucumber attached. That is the female flower. And it is this small cucumber that grows and enlarges into the cucumber we commonly see as food. Furthermore, cucumbers grow and enlarge their fruit without pollination. To draw an analogy, it might be like the chicken eggs you can usually get at the supermarket—essentially unfertilized eggs.
fruit
The part that envelops the seeds, perhaps akin to the white of an egg. This is where nutrients photosynthesized by the leaves accumulate, typically resulting in sweetness. This part is thought to exist to protect and sustain the seed. So why store nutrients? It's believed they accumulate attractive calories as nourishment to entice other animals to transport the seeds. That's why you can confidently bite into this part. Though, in humans, it usually doesn't end up sustaining the seed. Regardless, it's a captivating, “egg-like” part as an ingredient.
9. Eggplant
Eggplants are generally sold as purple vegetables, and the edible part is the fruit. They have a mild flavor, so they can be used in various types of dishes. There are many different varieties, and they come in a wide range of appearances, so you can enjoy different varieties in terms of both the look and taste of your dishes. Eggplant is a healthy vegetable composed mostly of water. Although it does not contain a large amount of nutrients, it contains a relatively balanced amount of vitamins and minerals. Among these nutrients, polyphenols, which are often highlighted, are contained in the colored skin. However, these components are easily washed away in water, so care may be needed when cooking. The real pleasure of eating eggplant is eating it with the skin on. When discussing cucumbers, I described the “fruit” as an ingredient with parts like an “egg.” Eggplant is also a “fruit,” and since you enjoy the skin as well, it's a vegetable where you eat the parts that give it its unique eating culture, similar to eating a whole egg, where the pleasure comes from eating it with the ‘shell’ intact. This is exactly why it's called “eggplant” in America.
10. Tomato
Tomatoes have become the quintessential staple vegetable, and it goes without saying that we are eating a ‘fruit’. Tomatoes are often eaten raw or cooked. Due to their high umami content, they are frequently used as a base or seasoning in dishes like ketchup, tomato sauce, and whole tomatoes, making them one of the most widely utilized vegetables. Furthermore, perhaps because of their usefulness, necessity, and high expectations, they are also one of the plants subject to extensive research and various breeding efforts. The interior of a tomato is broadly composed of three layers: the outermost “pericarp,” the middle “mesocarp,” and the innermost “endocarp.” This robust structure leads down to the “seed chambers,” where the seeds lie dormant. Within these “seed chambers,” an organ called the placenta connects to and protects the seeds. As noted earlier, tomatoes are ‘fruit’ parts, and like cucumbers or eggplants, they can be described as containing an ‘egg’. However, their highly complex and mysterious appearance might feel closer to the mystique of more animal-like structures. In other words, they might be vegetables that allow us to glimpse and imagine, in a more concrete way, something akin to the mystery within a mammal's womb during pregnancy.
Outer pericarp
The outermost part—the shiny surface you touch when holding a tomato. This is what we call the “skin.” When cooking, it's the part you blanch in boiling water and peel off to avoid that rough texture on your mouth and tongue.
Mesocarp
This is the part immediately inside the outer fruit skin. It's where numerous vascular bundles pass through, serving as pathways for nutrients and moisture within the fruit. This section, the mesocarp, constitutes the bulk of what we commonly eat as the fruit flesh. In other words, it's the fleshy part of the tomato, “The Tomato Meat.” This juicy section—might it be apt to liken it to subcutaneous fat?
Endocarp
This thin membrane-like skin forms the boundary between the mesocarp and the next layer of tissue. When handling tomatoes for consumption, it's a part that rarely draws attention and is seldom noticed. Next time you slice a tomato, it's worth taking a closer look and examining it carefully.
Annex
The seed chamber, written as “child's room.” True to its name, this is the actual room or area where seeds are stored and protected. To reach it, one must navigate the labyrinth of flesh formed by the outer, middle, and inner fruit layers. Considering this journey, the structure feels strikingly reminiscent of a pregnant uterus. Within this chamber, seeds attach to a part called the placenta, surrounded by a jelly-like substance that protects them.
Placenta
The placenta, which serves as the seed's resting place within the ovary, is a mysterious structure connecting mother and child—much like the placenta and umbilical cord in mammalian pregnancy, as its name suggests. Furthermore, the jelly-like substance within tomatoes when used as food is composed of a gelatinous material derived from this placenta. It evokes the image of amniotic fluid, adding an extra layer of mystery to its composition.
11. Bell pepper
Bell peppers, like cucumbers, eggplants, and tomatoes, are classified as fruits for the edible part. However, in typical cooking, we don't eat the entire fruit; instead, we remove the inner seeds and membranes as part of preparation. These seeds and membranes are the ‘seed chambers’ and ‘placenta’ surrounding the seeds. So, the edible part consists of the outer skin, middle skin, and inner skin—the fruit peel. Of course, you can also eat the seeds and membranes.
12. Daikon Radish
Daikon radish is a versatile ingredient used in a wide range of dishes—from large, long simmered dishes like oden to salads and pickles, and even as a refreshing condiment when grated. As the name “big root” suggests, its large root is the primary part used in cooking. Yet this remarkably thick and large daikon appears so substantial compared to other plants that one might question whether it truly is a root. Such roots are called ‘storage roots’ (chozōkon), which store water and nutrients. Among these, daikon belongs to a type of storage root called a ‘fleshy root’ (tanikukon). The daikon commonly found in stores is called “aokubi daikon” (green-top daikon), characterized by its green-tinged upper part. While we mentioned the upper part of the root, that green-tinged “blue section” is actually not the root itself. So what is it? Broadly speaking, it is the stem. More precisely, it is the “very first stem” – the part called the hypocotyl, which serves as the central axis of the entire plant from the seed stage until the true leaves emerge. The daikon radish is essentially this ‘hypocotyl’ and the ‘root’ section packed with nutrients. Earlier, we mentioned the ‘root’ plays a role similar to the intestines. Thinking about it that way, the daikon's ‘root’ might be like a belly storing super energy in the form of abundant fat. You often hear well-grown, large daikon radishes described as “well-fed radishes,” and that's exactly the feeling. While the root is the main edible part, the leaves are also often consumed. They're commonly used as furikake seasoning or in miso soup. You might not see it often, but the flowers can be eaten like nabana (rapeseed greens), and the immature pods before they form seeds can be eaten much like green beans. True to their daikon heritage, each part offers a refreshing aroma and a flavor reminiscent of the spiciness found in grated daikon. Furthermore, oil—a concentrated source of energy—can be pressed from the seeds. In other words, daikon is a plant where virtually every part can be consumed. There's a movement in some circles called “whole food,” which advocates eating vegetables and fruits with as little waste as possible to fully absorb a wide range of nutrients. Daikon might just be one of the most suitable ingredients for experiencing this concept firsthand. Incidentally, the part called the ‘hypocotyl’ is indeed the hypocotyl. As for where the ‘stem’ is located, it refers to the thin, roughly conical section from the top of the hypocotyl to the base of the leaves. Of course, it's edible.
Storage root
Among roots, thick—or rather, plump—roots that store large amounts of water and nutrients are called ‘storage roots’. The water and nutrients stored within them are used after a certain period, or when separated from the original parent plant. They are used when flowering and forming seeds, or when forming new leaves above ground. That's why they're packed with energy and make such a satisfying part to eat. Even if they're actually healthy, they're plump and round like fat.
Succulent roots
Among storage roots, those where the “main root”—the strongest, straightest root extending directly downward—becomes large and thick, and simultaneously the initial stem, the ‘hypocotyl,’ also thickens, are called ‘succulent roots.’ In other words, this type features the portion below the cotyledons, which sprouted first, becoming exceptionally large and thick. The straight, large, thick radishes commonly found in markets may symbolize growth that proceeded without any setbacks, growing straight and true.
hypocotyl
Formation begins at the seed stage, representing a part of “The Origin” that lies dormant within the seed. It can be thought of as the back muscles that provide the foundational strength for the first deadlift—lifting the initial cotyledons using the roots as an axis when sprouting. It continues to support the cotyledons thereafter, functioning like the crucial lower back and pelvis that maintain posture as the stem responsible for growth during the young and small stage.
13. Carrot
Like daikon radish, carrots are another vegetable where we eat the ‘root’ that firmly anchors itself in the earth. Morphologically, they are very similar to daikon, as carrots are also ‘storage roots’ and ‘fleshy roots’. True to this, they possess a stem portion derived from the ‘hypocotyl’, though it doesn't spread as widely as in daikon; it's only a slightly darker area near the base of the leaves. Also, while you might not see it often, the ‘leaves’ are edible too. Carrot leaves have a refreshing, slightly sweet, and cool aroma. Among those who enjoy them, tempura fritters made with both the carrot ‘root’ and ‘leaves’ are quite popular.
14. Taro
地下茎（チカケイ）
One of the delights of autumn and winter stews is the slightly slippery texture of taro. While it might seem most logical to explain that the edible part is actually a root growing underground... well, that's not quite how it works. The part we commonly eat as taro is not a ‘root’ at all. So what is it? It's a ‘stem’. In other words, the main body of the taro plant is the very tuber we eat—one might be tempted to declare triumphantly. Such underground stems, growing beneath the soil, are called ‘rhizomes’. Stems aren't exclusive to the above-ground parts; they also exist underground. From the above-ground stems, new shoots called ‘lateral buds’ emerge from the base of the petioles. Similarly, on the ‘rhizome’—which is also a ‘stem’—new ‘rhizome’ sections develop like these side shoots. While taro continues to multiply its main body underground in this way, even if considered a ‘stem’, it has a rather distorted shape for a stem. Such tubers are also called ‘tuberous roots’ and connect to the lower part of the stem section developing above ground. This plant achieves such diverse growth that its method of reproduction feels beyond imagination, making it difficult to express in terms of the human body. If forced to describe it, perhaps with a touch of occult-like thinking, one could liken it to a wound or wart on the body developing into a human-faced growth (human-faced layer), growing with its own will, eventually splitting off to become a separate individual. The taro root is the product of this bizarre, almost unbelievable method of reproduction. Additionally, in some regions, the leaf stalks of certain taro varieties are called “zuiki” or “imogara” and are eaten as a vegetable. Both the taro root and the leaves contain a toxin. If consumed raw, they can cause itching in the mouth or throat upon contact or ingestion. In severe cases, it can cause pain akin to being pricked by a hedgehog. Thorough cooking with plenty of water is necessary to neutralize this toxin. While this means we cannot casually recommend eating it whole like a daikon radish, it remains a delicious ingredient to enjoy.
Bulb
The underground stem that forms at the base of the stem extending above ground, enlarging into a spherical shape to store nutrients, is called a ‘bulb’. Its bud, or the starting point for the above-ground portion, is sometimes defined as a single point. When viewed as a tuber, it has a form that makes it easy to determine its top and bottom.
15. Potatoes
The potato, also known as the bareshō. While it can be enjoyed in many ways—as a snack in potato chips or as starch in products like potato starch—its versatility extends far beyond the realm of vegetables. But exactly which part do we eat? We harvest it as it rolls out of the ground. Since they grow underground, some might assume we eat the ‘root’. But if you've read this far, you might have guessed it's actually the ‘stem’. That's right, we don't eat the potato's ‘root’ but its ‘stem’ – specifically, its ‘underground stem’. Furthermore, among these ‘rhizomes’, there are varieties that develop swollen masses in various shapes, like spheres, at the tips of their branches. The potato belongs to one such variety, and these swollen parts are called ‘tubers’. Surprisingly, many things called ‘potatoes’ are actually ‘stems’, not ‘roots’. Much like the claim that the main body of a plant is the ‘stem’, the potato also seems to be primarily a tuber.
Tuber
Formed at the branching tips along the extension of the rhizome, the thickened stem that stores nutrients and water is called a ‘tuber’. Its shape is not only spherical but can also be variously lumpy. Its role and uses are similar to those of a bulb, and depending on the definition, the distinction between ‘bulb’ and ‘tuber’ becomes negligible. In the case of a tuber, multiple ‘buds’ exist on the tuber itself; these are the starting points from which shoots emerge above ground.
Summary
This time, we focused on designated vegetables as representative examples of those we commonly eat, and took a look at which parts of the plant we actually consume. How did you find it? Did you discover you've been eating unexpected parts? Or perhaps you simply feel like eating vegetables now? Plants, being living things, possess various complex functions and parts, each fulfilling diverse roles. Thanks to this, we can enjoy such a colorful and varied food culture. It might even lead to a deeper enjoyment of food—not just eating vegetables, but appreciating the specific vegetable you're eating right now.
Of course, beyond the vegetables introduced here, there are countless more vegetables, fruits, and even wild plants. Where exactly is that part for each plant? There are surely still many unexpected discoveries and surprises waiting to be found. Why not approach your next vegetable encounter with a little more curiosity and interest? The classic choice is the “strawberry.”
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