仙人掌俗名霸王树、玉芙蓉。主要生长在海滨沙滩等处。人们也常将其栽在花园或花盆中作为观赏药用植物。近来人们对仙人掌特别青睐。其一,仙人掌有一种奇特蓄水本能,白天在阳光照射下,为避免水分大量蒸发,它能自动关闭气孔,到晚上打开气孔吸收二氧化碳,放出氧气。室内栽培仙人掌可以增加新鲜空气,使室内中负离子浓度增加起到调节净化空气的作用。其二,仙人掌茎含 The cactus is known as the Overlord Tree and Jade Lotus. It is mainly grown on sandy beaches and other places. People often plant them in gardens or flower pots as ornamental medicinal plants. Recently, people particularly like cactus. First, the cactus has a peculiar water instinct. During the day in the sunlight, it can automatically close the air holes to prevent the water from evaporating. In the evening, the air holes absorb carbon dioxide and release oxygen. Indoor cultivation of cactus can increase the fresh air, so that the concentration of negative ions in the room to play a role in regulating the purification of air. Second, cactus stem contains