1. The appearance is geometric. The so-called geometric shape means that a pair of shapes should be as straight as possible, that is, the straight line from the tip to the bottom of the walnut should be as vertical and equally divided as possible with the horizontal plane at the bottom and the horizontal line at the widest point on both sides. Like in Chinese characters? Earth? Word or? Scholar? Word. Some walnuts have a congenital problem. Awkward? , such as the old tree south will stone. However, when we appreciate and collect, we should also choose a pair that is as straight as possible. Under normal circumstances, or to avoid? Awkward? , pursue? Perfect "

? Belly? Be full. The so-called fullness means that walnuts are fully mature? Belly? It should feel full, round and regular. Apart from the birth defects of some varieties, it is basically a sufficient? Mature? And during growth? Natural damage? The problem. Some playmates think? Full is actually a whole body? Drum? The problem? In fact, this understanding is not comprehensive. If walnuts are bulging all over, it is not good. But what? Drum? Must the place be? Drum? , shouldn't it? Drum? The place must be resolute, can't it? Drum? . Like some? Hat? What kind of walnut? Shoulder? The place must have a certain slope to be beautiful, and if you have to bulge it, it won't look good.

　? Edge? To be beautiful and generous, beauty refers to a pair of walnuts? Edge? The curve extends to the bottom in a beautiful, consistent, regular, natural and smooth way, and it should be as beautiful as a rainbow in the sky. Generosity means? Edge? As wide as possible? Wide? And the thicker the better, the better the side of the edge has a certain texture, not simple? Two petals? .

　4、? Sharp? To be complete and round, most varieties of walnuts are available? Sharp? Yes, probably among the varieties I have seen on the market, there is only the common name? Monkey head? There is no obvious tip. ? Sharp? To some extent, it is an important feature of walnut appearance. ? Sharp? Be sharp but not sharp, be? Positive? It should be round and thick and have a natural curve. Protect it? Sharp? It is very important to prevent falling, knocking and touching. Raise the tip? . Protecting the tip is the key to ensure the integrity of walnut products.

　5、? Stand? Walnuts with a stable shape should have a flat base and a tight tail. Some varieties, such as the bonnet, are inward because the edge extends to the bottom. Hey? Therefore, the base can't be horizontal, and some of them are inclined forward and backward, which should not affect the standing stability. Walnut can't stand lightly, no matter tall or thin, it must be solid. Some Qiu Zi's tail tips can't stand, which should be within the normal range. "

6. Heteromorphic walnuts should have both spirit and shape, and the key is pairing. The common olecranon, peanut and double petals on the market all belong to the category of special-shaped walnut. I've seen another one? Optimus Prime? , is a kind of Qiu Zi, like two sticks. The appearance of special-shaped walnut is complicated, which should be summed up in two points: first, it should be worthy of the name, lifelike and lifelike; Second, matching is good, which is also the most important and difficult aspect of heteromorphic walnuts. The quality of a pair of heterosexual walnuts directly affects the value. A single walnut may be worthless, and once it is matched correctly, its value will double. Nutritional value of walnuts

Walnuts are rich in nutritional value, including? Long live the son? Longevity fruit? The treasure of health? The reputation of. 86% of the fat in walnut is unsaturated fatty acid. Walnut is rich in copper, magnesium, potassium, vitamin B6, folic acid and vitamin B1, and also contains fiber, phosphorus, nicotinic acid, iron, vitamin B2 and pantothenic acid. Every 5g of walnut contains 3.6% water, 7.2g of protein, 31g of fat and 9.2g of carbohydrate.

Walnut contains 22.18% crude protein, in which glutamic acid is the main soluble protein, followed by arginine and walnut aspartic acid. 64.23% crude lipids, of which 93.5% neutral lipids; In neutral lipids, triacylglycerol is 82.5%, sterol lipid is 3.86%, and free fatty acid is 4.8%. Fatty acids in total lipids and neutral lipids are mainly sulfinic acid 64.48%-69.95% and oleic acid 13.89%-15.36%. The fatty acid in triacylglycerol is mainly linolenic acid 69.98; The unsaponifiable part of sterol ester is mainly? -sitosterol, with a small amount of campesterol, stigmasterol, oat sterol -5- enol and stigmasterol -7- dilute alcohol; Sugar 13%; A variety of free essential amino acids; Isoleucine, leucine, tryptophan, phenylalanine, valine, threonine and lysine, etc., the content of which is 47.5% of the total amino acids.

the fruit contains 1,4- naphthoquinone, juglone, 4-hydroxy -1- naphthyl-? -D- glucopyranoside, 4,8-dihydroxy -1- naphthyl-? D-glucopyranoside, potassium, calcium, iron, manganese, zinc, copper, strontium and other trace elements. Immature fruits are rich in vitamin C. The pericarp contains salicylic acid, p-hydroxybenzoic acid, vanillic acid, gentisic acid, p-hydroxyphenyl acid, gallic acid, p-coumaric acid, ferulic acid, caffeic acid, mustard acid, protocatechuic acid, syringic acid, and chlorogenic acid.

what does the exocarp of immature fruit contain? -Ammoniated juglone,? -Hydrogenated juglone? -Hydrogenated juglone -4-? -D- glucopyranoside, 1,4-naphthoquinone, 2- methyl-1,4-naphthoquinone, juglone, 5- hydroxy -2- methyl-1,4-naphthoquinone, 5- hydroxy -3- methyl-1,4-naphthoquinone, 2.3- dimethyl -5- hydroxy. Types of Walnut

Walnut's hometown is Iran in the west of Asia, and it was brought back to China after Zhang Qian went to the western regions in the Han Dynasty.

1. According to the origin, there are Chencang walnut, Yangping walnut and wild walnut;

2. According to maturity, there are summer walnuts and autumn walnuts;

3. According to the smoothness of the shell, there are light walnut and hemp walnut;

4. According to the thickness of the shell, there are two types, namely, thin-shell walnut and thick-shell walnut.

Existing Walnut Species in China

According to the book "Walnut in China", the existing walnut plants in China (including natural hybrids introduced from abroad and discovered) are divided into 3 groups and 8 species.

Walnut group: walnut and iron walnut

Juglans mandshurica group: Juglans mandshurica, Juglans mandshurica, Juglans mandshurica, Keppel walnut and heart-shaped walnut.

black walnut group: black walnut.

Walnut group

(1) Walnut, also known as walnut and peach, is one of the most widely cultivated varieties at home and abroad. Deciduous trees generally have a height of 1-2 meters, a maximum height of more than 3 meters, a trunk diameter of about 1 meter, a life span of one hundred or two years, and a maximum life span of more than 5 years. The crown of the tree opens in a semicircle or round head shape with a diameter of 6-9 meters. The bark is grayish white to dark brown, the bark of young trees is smooth, and the old trees have irregular shallow longitudinal cracks. The branches are thick and smooth, and the tender branches are green when they are born, but they can also be slightly red in early spring, and turn bright gray or grayish brown after stopping growing, showing white lenticels. The pith of annual branches is large and the xylem is soft, and the pith gradually becomes smaller with the increase of age. The leaves are odd pinnate compound leaves, alternate, 3~4 cm long, the compound petiole is round, the base is hypertrophy with glandular points, and the leaves are triangular after shedding. 5-9 leaflets, oblong, obovate or broadly elliptic, with short stalks, slightly protruding tips at the apex, and the entire leaf margin or slightly serrate.

The mixed buds are mostly round, and the vegetative buds are triangular and scaly, which are inserted between axils. Monoecious, heterogamous, the male inflorescence is catkin drooping, 8-12 cm long, and the perianth is 6-lobed. There are thousands of florets in each male inflorescence, and there are 12-26 stamens in each floret. The filaments are extremely short, and the anthers are apricot yellow when they mature. Female flowers have 1-3 clustered branches, perianth 4-lobed, stigma 2-lobed, occasionally 3-4-lobed, pinnately curved, light green or pink, densely villous outside the ovary, one room, lower position. The fruit is artistic, round or oblong, with a diameter of 4-5 cm, a thin exocarp, a smooth or fluffy surface, green and yellow-white spots; Mesocarp is fleshy; There are grooves or wrinkles on the surface of endocarp bone (called fruit shell), and there is a seed in the fruit shell, called seed kernel, that is, the edible part, which is brain-shaped and covered with a light yellow or yellowish brown thin seed coat with obvious or inconspicuous veins.

(2) Iron walnut is also called Yangbi walnut, and the cultivated type is mostly called pickled walnut and tea walnut. The main difference between Juglans regia and Juglans regia is that there are 9~13 leaflets, which gradually become smaller from bottom to top. The leaflets are elliptic and lanceolate, and the top leaflets often degenerate into linear bodies with a length of 1~1.5 cm, so they are like even-numbered pinnate compound leaves, and the leaf margin is entire or slightly serrated. The fruit is oblate and the shell is obviously wrinkled. Shells can be divided into thin and thick, among which cultivated fruit shells are easy to crack, while wild fruit shells are difficult to crack. Other morphological characteristics are similar to walnut.

Juglans mandshurica group

(1) Juglans mandshurica

is also known as Carya cathayensis, Juglans mandshurica, Juglans mandshurica and so on. Deciduous trees, trees up to 2 meters high. The crown is broadly oval, the bark is gray or dark, smooth when young, and shallow longitudinal cracks when old. Buds are triangular and yellow-brown. Odd-pinnate compound leaves, 6-9 cm long, 7-17 leaflets, extremely short or sessile stalks, oblong or oval, with fine serrations at the leaf margin and dense hairs on the back. The male inflorescence is 9-12 cm long, with small flowers on the densely hairy floral axis. The female flowers are fuzz, and the stigma is 2-lobed, which is purplish red or bright red. Infructescence is usually 4-7 fruits, the fruit is ovoid or ovoid, the apex is sharp, the shell surface has 6-8 ridges and irregular deep grooves, and the shell and inner partition wall are thick and hard to take kernels.

(2) Wild walnut

Deciduous trees or small trees, sometimes shrubby, are 5-2 meters high or higher. Odd pinnate compound leaves can be as long as 1 meter, with 9-17 leaflets; Leaves ovate or oblong, 8-15 cm long, female inflorescence 6-1 florets, strung. The fruit is ovoid, with sharp apex, small fruit, hard shell, 6-8 sharp edges, and bone in the inner partition, so it is difficult to take kernel.

(3) Juglans regia

is also known as wenwan walnut. Mainly distributed in Beijing, Hebei, Liaoning and other places, it is a natural hybrid of walnut and Juglans mandshurica. Deciduous tree, 1~2 meters high, with silver-gray bark. Odd-pinnate compound leaves are 45~8 cm long, with 7~15 leaflets, whole or shallowly serrated, and short hairs on the back of leaves. The male inflorescence is 2~25 cm long, and the female inflorescence is terminal, with 2~5 florets clustered. The fruit is round or oblong, with a sharp apex and a diameter of 4~5 cm. The shell is thick and not easy to crack, and the bone of the inner partition wall is developed, so it is difficult to take kernel.

(4) Keppel Walnut

is also known as Ghost Walnut and Japanese Walnut. Produced in Japan, introduced to China in 193s, and grown in Liaoning, Jilin, Shandong, Shanxi and other places. The tree is 2 ~ 25m high. 9~19 leaflets, ovoid. The male inflorescence is 15~2 cm, and the female inflorescence is terminal, with 5~2 small flowers strung. Ovary and stigma are purplish red. The fruit is oblong, with a sharp apex and dense glandular hairs. The shell has 8 obvious ridges and carved points, and the shell is thick and the inner wall is bony, so it is not easy to take kernel.

(5) Heart-shaped walnut

is also called Ji walnut. Originally from Japan, it was introduced to China in 194s, and it was cultivated in Liaoning, Jilin, Shanxi and Inner Mongolia. Its main morphological characteristics are similar to those of Keppel walnut, and the main difference is fruit reproduction. The fruit is flat and heart-shaped, with smooth shell surface, sharp apex, thick shell, no inner partition wall, and easy cracking at the suture line, so it can be whole kernel.

black walnut

black walnut includes 16 tree species, which are distributed in North America and Latin America. Among them, the most economically valuable tree species is the eastern black walnut (J.nigra), which is widely distributed in the eastern half of the United States and the south of Canada. Nuts are the largest among the 16 tree species, and the wood is the best. They are excellent furniture materials and plywood talents.

native to north America, black walnut was introduced to China in 1984 and grows in Beijing, Nanjing, Liaoning, Henan and other places. The height of the tree can reach more than 3 meters. Bark is dark brown or grayish brown, with deep longitudinal crack. The shoots are pilose. 15~23 leaflets. Oval, with irregular serrations on the leaf margin, the surface of mature leaves is smooth and the back is hairy.

The male inflorescence is 5~12 cm long, the florets have 2~23 stamens, and the female inflorescence has 2~5 florets clustered at the top of the branch. The fruit is spherical, with small bumps and fluff on the surface. Nut apex is slightly pointed, and the shell surface has irregular deep grooves. The shell is thick and difficult to crack. Its endocarp is often used as decoration.

hickory

Carya cathayensis Sarg., also known as Juglans mandshurica and Juglans mandshurica. It is a deciduous tree belonging to Carya of Juglandaceae. There are about 2 species, 4 of which are native to China. In 1984, Zhejiang Forestry College discovered a new species in Jinzhai, Anhui. There are 11 species native to North America, among which the longevity fruit-called Bigen Fruit is one.

Carya cathayensis, 1-2m in height and 3-6cm in DBH; The bark is smooth, gray and smooth; Branchlets are thin, new branches are dense, and orange glands are peltate. Later, the glands are gradually sparse, and the annual branches are purple-gray. The upper end is often sparsely pubescent, and the lenticels are round and sparse.