Name: Populus tomentosa

Scientific name: Populus tomentosa

Nicknames: Populus euphratica, Populus euphratica

Populus of Salicaceae.

Category: deciduous trees

morphological character

Deciduous tree, 30m high, diameter at breast height lm, straight trunk, grayish green to grayish white bark, rhombic lenticels, dark gray at the base of the old tree, longitudinally split. The young branches are hairy and then fall off. The leaves and buds are ovate, the long branches and leaves are broadly ovate or triangular-ovate, with a length of 10- 15 cm, the apex is short and tapering, the base is heart-shaped or truncated, the teeth are deep or wavy, the lower part is densely villous, and then gradually falls off. The upper part of the petiole is flat, 3-7 cm long, and there are often 2-4 glands at the top. Short branches and leaves are ovate or triangular-ovate, the apex is acuminate, the lower part is hairless, the teeth are deeply wavy, the petiole is flat, slightly shorter than the leaves. The flower buds are ovoid or subglobose, the male inflorescence is 10- 14cm long, the bracts are densely hairy, and the stamens are 6-12; The female flower is oval, and the inflorescence is 14cm long. Fruit conical or oblong, 2-lobed. It blooms in March-April and bears fruit in April-May with small capsules.

The related species Populus euphratica is divided into five factions, namely Populus euphratica, Populus macrophylla, Populus cathayensis, Populus nigra and Populus euphratica.

(1) The bark of the sect. Poplar of Poplar Sect is usually gray and smooth, and the base of old trees is rough. Leaves are fluffy, or under long branches and leaves, short branches and leaves are fluffy or glabrous. Bracts split into strips with long hair at the edge of lobes. Fruit oblong, 2-lobed. Besides Populus tomentosa, there are Populus alba, Populus davidiana, Populus hopeiensis, Populus euphratica, Populus tomentosa, triploid Populus tomentosa and Populus euphratica. Yan Ling's comparison is as follows:

① The biological characteristics of triploid Populus tomentosa are similar to those of diploid Populus tomentosa, but it grows faster than diploid Populus tomentosa, with stronger stress resistance and better material quality.

②84k Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang× Yang × Yang× Yang× Yang× Yang. The tree is tall and straight, with beautiful shape, smooth trunk, blue-gray skin and buds close to the trunk. The leaf blade is round, the front is dark green, the back is densely covered with white fluff, and then gradually falls off. It is a male clone, which has no "flying floc" and will not pollute the environment. Rooting is easy, seedlings and young trees grow fast, with good materials and strong wind resistance and stress resistance.

(2) Sect of bark. The white leaves of Populus macrophylla are flaky and rough. The bud is conical, slightly gelatinous and hairless. Short and long branches are nearly round, the base is heart-shaped or deep-heart-shaped, and the top of petiole is slightly flat. Disk deeply divided, persistent; Stamens 12-40, anthers oblong and apiculate; Ovary pilose, style longer, stigma 2-3-lobed. Fruit indumentum, 2-3(4)-lobed. There are mainly Populus macrophylla.

(3) Sect of bark. Tamahaka of Populus davidiana is longitudinally split, with large buds, rich gum and fragrance. The lower leaves are often white, the long and short leaves are different in shape, and there is no translucent edge at the edge; Petiole rounded or nearly quadrangular, grooved. Stamens 18-60, stigma 2-4-lobed; Style short or absent. Fruit 2-4(5) cleft, disk persistent. In Yanling, there are many cultivated plants:

① The bark of Populus simonii is grayish green in young age and dark gray in old age, with longitudinal cracking. Young branches and twigs are angular, while old branches are round and hairless. The bud is slender and the apex is long. The leaves are rhombic-ovoid, rhombic-elliptic or rhombic-obovate, 3-12cm long and 2-8cm wide. The petiole is round and has the characteristics of cold resistance, early resistance and wind resistance.

② Populus tomentosa is called Populus macrophylla in Henan Province. The bark is brown, flaky and hairless. The bud is hairless, and the germinated branches and leaves are oval, 25cm long,15 cm; Wide; Short branches and leaves ovate or broadly ovate, 7- 14cm long, tapering at the top, rounded or nearly cardioid at the base.

(4) Bark group. Aegeiros of Populus deltoides is longitudinally split, and the buds are rich in gum. Leaves are usually triangular or diamond-shaped, with sharp tips, flat or broadly wedge-shaped bases, obtuse serrations, translucent leaf margins, green surfaces, stomata and flat petioles. Fruit 2-4-lobed, disk persistent. Yanling cultivation mainly includes:

① Populus davidiana's crown is broad, conical, with sparse lateral branches and nearly whorled; The bark is gray to grayish brown with a shallow base. Long branches and sprouting branches are angular, grayish green to grayish white, and short branches are yellowish brown. The buds are triangular cone-shaped, with short branches, and the leaves are triangular or triangular oval, with a length of 8- 1 1 cm and a width of 6-9 cm.

② 107 Populus euramericana hybrid originated in Italy and was introduced to China in 1984. The trunk is tall and straight, the bark is gray and thick, the branching angle is small, the crown is narrow, the lateral branches are thin, the leaves are small and dense, full of crowns, and female. It has the advantages of fast growth, cold tolerance and pest resistance.

③ 108, an artificial hybrid of Populus deltoides and Populus deltoides, originally from Italy, was introduced to China in 1984. The trunk is straight, the cone is small, the crown is narrow, and it is a female plant. Fast growth, strong wind resistance, pest resistance, excellent material, drought resistance and low temperature resistance. Compared with 107 poplar, its growth is similar, but it is more cold-resistant.

The excellent varieties introduced and cultivated in Yanling County are 2025, 200 1 series, transgenic insect-resistant poplar and so on.

(5) The budding of sects. Taranga of Populus euphratica is gelatinous and hairy. The leaves are diverse in shape, gray-blue on both sides, and only the lower part has pores; Petiole is round. Disk membranous, lobed or deeply lobed. Have sharp teeth and fall early. Yanling has sporadic cultivation.

Ecological habits like warm, cool and humid climate. In places where the temperature difference between day and night is large in early spring, the bark is often frozen and cracked, commonly known as "broken belly disease". In warm, hot and rainy climate conditions, diseases and pests are prone to occur and poor growth. It grows rapidly on deep, fertile and moist loam or sandy loam. In arid and barren saline-alkali land and desert land with little accumulated water, poor growth and serious pests and diseases are easy to form "small old trees" Slightly salt-and-alkali-tolerant, big trees are water-resistant and moisture-resistant, with deep roots, strong rhizosphere germination and smoke resistance.

Distribution of origin

Originated in China and distributed in China, it starts from southern Liaoning and Inner Mongolia in the north and reaches the Yangtze River in the south, with the middle and lower reaches of the Yellow River as a suitable living area. It is vertically distributed below the altitude of 1200M, and mostly occurs in places with deep soil layers in low mountains and plains. There are big trees beside the ditches and dams at an altitude of 1900M near Kunming, which grow well.

Growth habit

Strong positive tree species. I like cool and humid climate, and I am prone to diseases in warm and rainy climate. I don't have high requirements for soil. I like deep and fertile sandy loam. I can't tolerate too much drought and too thin. I can grow with a little alkali, and my trees can withstand moisture. Anti-smoke and pollution. With deep roots, developed roots, strong germination and rapid growth, it is the longest tree species in poplar, and its life span can reach 200 years.

type

Most people make a living by grafting, burying strips, leaving roots, layering and tillering. Populus canadensis can also be used as wood budding or tree grafting, with high survival rate.

Sowing: the seeds should be harvested immediately after the fruit is ripe, with a 1000-grain weight of 0.45g and a germination rate of about 96%. Carefully prepare the soil before sowing, sow, cover the soil by 0.5cm, and suppress after sowing. 1 year-old seedlings have an average height of 62.6cm and a ground diameter of 0.35- 1cm.

Attention should be paid to picking lateral buds in time at seedling stage to protect the high growth of terminal buds.

Decorative application

Populus tomentosa is tall and straight, with majestic posture, thick leaves, low growth, strong adaptability and long life. It is an excellent greening tree species in urban and rural areas and industrial and mining areas. It is also often used as a street tree, garden tree, yard shade tree or to create a shelter forest to prevent such construction; Can be planted alone, or in clusters or groups around buildings, lawns, squares and waterfront areas; Plant in groups around streets, expressway, school playgrounds, factories and pastures.

1. Poplar is the most common tree in northwest China. As long as there is grass, there is the shadow of poplar. Poplar is not very particular about living conditions. Roadside, beside the ridge, where there is loess, there is her survival. She doesn't chase rain, and she doesn't long for sunshine. As long as she can water the hardened land a little, a poplar will take root and sprout. As long as a little space is set aside for weeds to survive, she will decorate the yellow land and hold up a piece of green. She doesn't need to fertilize and water like a delicate lawn. As long as she doesn't use a knife and axe to chop, and gives her a relaxed environment to absorb free air, she will hold her head high. She never rejected the land where she grew up. She is not a vine, rooted in poor soil, happy-go-lucky, otherwise, because she belongs to the grassroots. Although poplar was born in poverty, it is the most concerned about the quality of life. There is still ice in the soil, and the spring breeze is still chilly. Green shoots have sprouted from her branches. Under the heavy pressure, every bud and leaf of her is striving for progress, never bending down to beg, and there is no flattering face. In the autumn wind, although the leaves have been stripped, the thin branches are still full of essence, and the branches stand upright and hold their heads high. In the severe winter, facing the sword, she still stands on the cold yellow land, with proud branches, silent trees and voices. At this time, the noble flowers and plants, however, are in the greenhouse, receiving the nutrients sent to the leaves and roots, lazily killing the bloodless days. Poplar's temperament is civilian, but it is the richest. She can be used as firewood, furniture, purlin and farm tools. Like the yellow land where she grew up, it is unpretentious. In some people's eyes, she will almost forget her existence. But for the barren yellow land, she is a brave person. Throughout the year, she stayed and decorated, which reduced the poverty and loneliness of the yellow land and increased the vividness and beauty, because her roots have been integrated with the yellow land. Poplar did not expect to transplant and migrate, even if her fallen branches and leaves were corroded by soil, it would add some nutrients and vitality to this yellow land. Under the thick loess, the immortal life of poplar is surging, and the yellow land is crisp and green. The sower sowed another poplar, and in a few years, the poplar will become a bigger green again. My respected teacher is the eternal poplar, and we are the green extension of this poplar.

Gobi desert is a landform on the edge of desert. It is mainly composed of gravel and coarse sand.

Its main characteristics are excellent air permeability, lack of water on the surface, few plants, only some drought-tolerant plants such as willow and camel thorn grow, and it is often windy.

The main reason for its formation is flood alluvial.

When there is a flood, especially in mountainous areas, due to the gradual weakening of flood energy, the following geomorphological characteristics are formed in the flood-stricken areas: large rocks are piled up at the nearest mountain pass, and the rocks outside the mountain become smaller in turn;

Then there are fists and fingers-sized stones. Due to years of sunshine, rain forest and strong wind erosion, the edges and corners gradually become rounded and become what we call stones (scientific name is gravel). In this way, the Gobi desert was formed.

The finer sand and mud are alluvial and drift farther, forming a distant desert.