Larix

's
1
genus. Deciduous trees, trunk straight; Leaves, bud scales, male scales, scales, bead scales and seed scales are arranged in a spiral. The leaves are scattered on the long branches, in the short branches are cluster-shaped, inverted needle-shaped line, soft, the upper middle veins how much bulge, the following sides have several porous lines, the leaves have
2
usually edged resin channels. Female and male, female and male ball flowers are born alone at the top of short branches, male ball flowers most male, each male with
2
flower medicine, medicine room cracking, pollen airbag-free; Ball fruit upright upward, when mature, usually purple-red at an early age; seed scale leather, survival; scales short and narrow, do not reveal or slightly reveal, or scales longer than the scales, exposing part of the straight, curved or reverse fold; seeds with long membrane wings, the base is wrapped in seed wings, seed skin resin-free sac. Chromosomal base
x x 12
.is about
18
species, distributed in the northern hemisphere, in Europe and Asia and North America are beyond the north regression line, up to
63
degrees north latitude to
72
degrees
30
degrees, the southern line of the distribution area about
40
degrees north latitude. However, in northern China, Hengshan, Wutaishan, Lu Liangshan, Qinling to Hengshan, Himalayas, up to
20
degrees north latitude
10
. It is one of the main tree species
representative
cold and wet conifer forests in the northern and mountain cold temper zones and in the cold climate. China produces
10
species, distributed in Heilongjiang, Jilin, Liaoning, Hebei, Shanxi, Shaanxi, Gansu, Xinjiang, Tibet, Sichuan and Yunnan provinces and regions.Deciduous pine plants in the early third period has appeared in Eurasia, to the fourth century due to the impact of temperature decline, the distribution of deciduous pine gradually expanded, and then with the late ice temperature rise, its distribution area gradually retreated northwards and to the mountains, breeding so far, the formation of the current distribution pattern. Deciduous pollen and spheres were also found in late-renewal formations in northeast China and the North China Plains, such as Huma, Harbin, Raohe and Beijing.Deciduous pine is a cold-resistant, magpie, drought-resistant and barren shallow root tree species, happy cold climate, more adaptable to the soil, there is - determined water-resistant wet ability, but its growth rate and soil soil fertilizer conditions are closely related, in the soil moisture or soil moisture too much, poor breathing conditions, deciduous pine growth is not good, or even death, over-alkali soil is not suitable for growth. Deciduous pines usually form pure forests, sometimes mixed with fir, spruce, and hardy pine or broad-leaved trees. In China, the widely distributed deciduous pines are: deciduous pines (also known as Xing'an deciduous pines), North China deciduous pines, Siberian deciduous pines, sequoia and its variants of large fruit sequoia and so on.The deciduous pine genus is divided into two groups according to the shape of the spherical fruit, the length of the scales and whether the branches are sagging: sequoia group cylindrical or egg-shaped cylindrical, the scales are longer than the scales or near equidioids, significantly exposed or exposed, and the lower branches are sagging (home-made Tibetan sequoia, Himalaya sequoia, large fruit sequoia, Sichuan sequoia, sequoia belongs to this group). Deciduous pine group ball eggs round or long egg round, scales shorter than the species scales, do not reveal or tip exposed, small branches do not sagging (national deciduous pine, yellow flower deciduous pine, North China deciduous pine, Siberian deciduous pine and the introduction of Japanese deciduous pine, European deciduous pine belongs to this group).Deciduous pine trunk straight, less, the difference between heart and edge material is significant, the material is tough, the structure is slightly rough, the texture is straight, is the pine plant corrosion resistance and strong sociology of wood, suitable for construction, electric poles, bridges, boat cars, pillows, eucalyptus, ore pillars, furniture, appliances and wood fiber industrial raw materials and other materials.。