Why does it seem like there are no salty fruits?

This article is authorized to be reproduced from: Bowuzazhi (ID: bowuzazhi)

In autumn and winter, there are many more fruits on the shelves of supermarkets. There are so many kinds that it feels like you can buy a different one every day for a month. Seasonal fruits are sweet and delicious. Sometimes I accidentally eat too much, and it is inevitable that I want to eat something salty to balance the taste. In a flash, I realized: Why have I never eaten salty fruits? It seems that when it comes to the taste of fruits, it is nothing more than sour and sweet. Is there no room for "salty party" in natural fruits? As a result, I found that not having eaten it does not mean that there are really no salty fruits——

Part 1

Two kinds of "fruits" on one tree?

This plant that can bear "salty fruits" is called Rhus chinensis, which belongs to the genus Rhus chinensis of the Anacardiaceae family. Just hearing the name, it makes you salivate, just like the nine-processed preserved plums.

Rhus chinensis is not a rare plant. It is distributed in most parts of the country and has different names in different places. The most widely known name is "gallon tree".

Image source: uekipedia.jp

The leaves of the gallnut tree are also somewhat peculiar. Li Shizhen also observed this keenly. He wrote in "Compendium of Materia Medica": "The wood is like a Chinese toon, and its leaves grow in pairs, long and with teeth... Under the main leaves, there are straight leaves on both sides of the nodes, attached to the stem like arrow feathers." Translated, this means that this tree actually has leaves on its leaves. The young stems and leaves of the gallnut can be eaten as wild vegetables or fed to pigs. The gallnut tree is actually a pinnate compound leaf. The so-called main leaf is the leaflet growing on the petiole, and the straight leaf is the petiole with "wings". The petiole or stem of some plants will become flat and wide, specialized into a leaf shape, which is a false leaf. Not only is it similar in shape, but its actual function is also similar to that of a real leaf, and it can also photosynthesize. Gallnuts often grow in places like petioles. Let's talk about gallnuts again. Gallnut is a common medicinal material, and the Gallnut tree is named after it, so many people take it for granted that Gallnut is the fruit of the Gallnut tree. Obviously, this is a misunderstanding - the real fruit of the Gallnut tree is called Rhus chinensis, and Gallnut is not a fruit at all, but a gall. It is a hyperplastic "tumor" produced when aphids such as Aphis hornkinensis parasitize on Rhus chinensis and stimulate the leaf tissue. Leaves with galls are like severe allergic reactions, with a bunch of scary "pimples" appearing, which is a bit disgusting at first glance.

If you don't know what "galls" are, don't worry, you will understand after looking at a few more pictures. These "tumors" are the homes of the baby insects, and they will expand further as they reproduce. But when the time is right, these natives must be "sent away" in time to prevent them from wanting to "divide the house and tear down the family" when they have grown wings. Another alias for the Chinese gall is "a warehouse of hundreds of insects", and the pictures speak for themselves. Cut open a gall, and those on the gall wall are not bread crumbs, but fresh aphids. The "white sesame" in the corner is not only the secretions of aphids, but also the corpses of "elders". The most important thing for a family is to be neat and tidy.

Image credit: Dr. Kazumasa Oshima / academist-cf.com

The gallnuts we see now are usually dried and processed, and look rustic. But in fact, fresh gallnuts look very fresh and small, no wonder people mistake them for the fruit of the tree.

Mature gallnuts have the same color as peaches. Image source: e-info.org.tw

In addition to its medicinal uses, gallnut has an unexpected use - dyeing black. In addition to dyeing cloth, it is also the core "black technology" of hair dyeing and teeth tanning in ancient times. Because gallnut is rich in tannin, it can react with iron salts to form a non-water-soluble stable black substance, making it a good black dye.
Textiles dyed with gallnut dye

Image source: wbg.cas.cn

Part 2

The real fruit "salt substitute"

After talking about the Gallnut, which is the most popular fruit, let's talk about the "Saltroot" which should have been the most brilliant but became a small and transparent fruit. Although it is the real fruit of the Gallnut tree, it is not very good-looking. It is the kind of wild fruit that you would not notice even if you pass by. The fruit of the Saltroot is very small and very inconspicuous when it is immature. October to November every year is the season when the Saltroot matures. At this time, the clusters of fruits on the branches will turn reddish brown. There are many of them, but each one is only the size of a mung bean, and the key is that there is a big core. It is really the kind of fruit that you put in your mouth and lick it around and it is gone. Even melon seeds have more meat than it.

Mature Rhus chinensis. Image source: Internet

Although the size of the salt-fuzzy fruit is small, it is delicious because its peel is often covered with a layer of "salt frost" on it, which is very magical. This is why it is called salt-fuzzy fruit. However, the taste of this fruit is not just salty, but salty and sour. Some people say that some of them are also a little sweet. In short, this description is more and more like the "salty plums" we eat. People in some places still use it to soak water instead of vinegar. In ancient times, salt was not as convenient and cheap as it is today. Salt was a "luxury necessity", so crops like salt-fuzzy fruit that can produce saltiness and are relatively common are naturally one of the ideal "substitutes" for salt. Salt nut has a long history of being used as a "salt substitute". In the Tang Dynasty, "people in Lingnan took the seeds and ground them into powder and ate them. The sour and salty taste quenched thirst and could prevent malaria." "Compendium of Materia Medica" also records that "there is a thin layer of salt on the thin skin outside the kernel, which is eaten by children. People in Yunnan and Sichuan collect it as wood salt." People in many places take salt from the fruits of salt nut, so salt nut has different names in different places. "People in Sichuan call it sour barrel. It is also called vinegar barrel. People in Wu call it salt bran. Rong people call it wood salt." Salt nut can solve the temporary emergency of using salt, but it cannot solve the need for a lifetime.

The ancients did not understand chemistry and thought that Rhus chinensis could be used as edible salt because it was salty. But in fact, the salt frost is different from the edible salt we usually eat. It is the crystallization of calcium malate, which is also the source of its saltiness. Therefore, the fruit is not like sodium chloride, which has only pure saltiness. Of course, it can be used for seasoning, but it cannot provide the sodium element needed by the human body and cannot replace real salt. So once salt became a readily available supply, Rhus chinensis became an "outdated internet celebrity". Now it is not as popular as the more famous Gallic chinensis, and even the name of the tree has been replaced by Gallic chinensis. However, this fruit is still very useful when surviving in the wild or having a picnic outdoors.

Source: Museum