China Taxus var. Evergreen tree with light gray bark, longitudinally split into thin strips; The top of bud scale is blunt or slightly pointed, and the base of branchlets falls off or partially persists. Leaves in 2 rows, nearly sickle-shaped, with a length of 1.5-4.5 cm. There are no mastoid horny processes in the midvein on the back, or there are sporadic distribution, or there are 1 to several mastoid horny processes on both sides of the midvein adjacent to the stomatal area, which is different from the stomatal area in color, light green and obvious in edge width. Seeds obovate or columnar oblong, 7-8 mm long, upper part usually wider, born in red fleshy cup-shaped aril. Seeds can extract oil; Bark contains tannin; Wood can be used as processing material. Both Nanjing and Shanghai are cultivated; Breeding with seeds can also be done by cutting. It is distributed in various provinces and regions south of the Yangtze River basin, as well as Henan, Shaanxi and other places. Wild plants under special state protection.
Taxus chinensis var. mairei var. mairei in China is one of the endemic components in subtropical to warm temperate zones in China, which is often distributed in broad-leaved forests. Shade-tolerant trees like warm and humid climate and generally grow in humid places in the hinterland of the foot of the mountain. It naturally grows in acidic soil rich in humus, such as valleys, streams and gentle slopes below 1000m or 1500m above sea level, and requires that yellow soil, yellow brown soil, neutral soil and calcareous soil with high fertility can also grow. Drought-resistant and barren, not resistant to low-lying water. Strong adaptability to climate, annual average temperature 1 1- 16℃, minimum extreme value-1 1℃. Strong germination ability, sprouting twigs are common on the trunk, but the growth is slow. Less pests and diseases, long service life.
Taxus media, native to the United States and Canada, is a natural? Taxus media map hybrid varieties. It can be planted in most areas of our country. Fast growth, measured annual height growth of 40-90 cm, the highest is 60-70 cm, which is 300-700% of the growth of China yew (China yew, Yunnan yew, etc.). ). The biomass accumulation of 3~4 years old is 600~800 plants per year, and the fresh raw material produced in 5 years old is more than 1.5kg, which can be used to extract paclitaxel. In the second year, new branches and leaves can germinate, and their biomass is still greater than that of the first year.
In the mid-1990s, seedlings of Taxus canadensis introduced from China were planted in Sichuan. According to the testing of authoritative organizations, the biological characters of introduced Taxus media are stable and there is no variation. The content of paclitaxel is close to the origin, and the content in some samples is higher than that in the origin. Taxol in natural yew is generally distributed in bark, and the utilization rate of the whole plant is low.
Taxol is contained in all parts of Taxus media, and the content of branches and leaves is above 0.03%, and the root part can reach 0.06%. The whole plant is used to extract paclitaxel, which has high plant utilization rate and high comprehensive economic value after deep processing.
The taxol content of wild yew, including domestic varieties, is generally between 0.004~0.0 1%, and that of Taxus media is 0.03~0.06%, which is 8~ 10 times that of natural yew, and it can be planted in most areas of China.