Citronella.

The fennel is a perenn perennity herb. Important tropical spice crop. Native to the tropical regions of Southeast Asia, has been widely planted in the world tropical, subtropical areas. The main producing countries are China, Indonesia, Sri Lanka, Guatemala. China's main origin is Guangdong, Taiwan, Fujian, Guangxi, Yunnan also have a small amount of cultivation.plant height 60 to 150 cm, strong division, thick, the base has residual leaves; As an economic cultivation of the champs are mainly two kinds: Javanese-type fennel leaves long and wide, high yield, oil yield of about 1.3%, aldehyde, alcohol content is high, in the world's champs production has an important position. Ceylan-type champs are narrow and hard, with an oil yield of 0.37 to 0.4%, mainly in Sri Lanka. Xiang Maoxi high temperature humidity and sunny environment, with an average annual temperature of 24 to 26 degrees C, annual rainfall of 1700 to 1800 mm, relative humidity of 80 to 85% of the climatic conditions, as well as deep, fertile, well-drained acidic sand loam is appropriate. Plant in sub-plants. Cultivation should choose 1.5 to 2 years of raw (stem thick about 0.8 to 1 cm) of strong seedlings, in the rainy season trench planting, planting distance of about 70×90 cm. After planting timely weeding, fertilization, soil cultivation, 6 months later can start harvesting, can be harvested for 4 consecutive years. Leaves are cut every 60 days during high-temperature and rainy seasons, and leaves are cut once every 120 to 150 days during low-temperature dry seasons. The average annual yield of fresh leaves 500 to 1000 kg or more (fold oil 5 to 10 kg). The main pests and diseases are leaf disease, black leaf ticks and so on.

oil steamed from the stems and leaves, the main ingredients are vanilla aldehyde, vanilla alcohol and vanilla leaf alcohol. Widely used in the preparation of
,
, perfume, powder, toothpaste and other daily necessities. Vanilla aldehyde can be processed into hydroxyl vanilla aldehyde, lemon aldehyde, etc., as an important food spices. Thatch oil also has sterilization, anti-inflammatory, soothing, live, pain relief and other effects.