"Little Nike" is a cactus, living in the vast Sahara desert. The climate there is hot, dry and rainless, and the living environment is extremely difficult. Although this home is full of yellow sand, little Nike still likes its home very much.
The yellow sand monster also lives in the desert. He has a bad heart. He always wants to monopolize the desert. He always tries to torture the plants in the desert and drive everyone out of the desert.
Little poplar left, little fir left, little elm left... Soon, there was only "little Nike" plant left in the desert.
"Little Nike, get out of here. Otherwise, I will be rude to you. " The yellow sand monster puffed up his cheeks and blew the yellow sand.
"I'm not afraid of sand!"“ "Little Nike" face unchanged to stand a small body, let the yellow sand monster rampant.
"It seems that you don't know who is the king in the desert if you don't have a taste of it!" The yellow sand monster decided to cut off the underground water source of "little Nike" and not give him water.
To Wong Sha's surprise, "little Nike" was still energetic without drinking water for several days“ I'll let the sun dry you The yellow sand monster puffed up his cheeks and blew away the sand pile beside "little Nike", exposing "little Nike" to the scorching sun.
The sun is shining on little Nike. The yellow sand monster thought that "little Nike" would be soaked in the sun, and could not help laughing happily. But after a long time, little Nike didn't sweat at all. Originally, "little Nike" leaves grow into sharp thorns, greatly reducing the evaporation of water, so that the body's water is not easy to lose.
Wong Sha tried his best to dry up the water in little Nike's body, but failed. The yellow sand monster had nothing to do, so he had to run away: "since you can't get rid of you, you can live here!"
"Fortunately, I've been on guard for a long time. I'm full of water in my body!"“ "Little Nike" looked at his fat and fleshy body, like a reservoir, and laughed happily. It turned out that when the rainy season came, he had absorbed a lot of water and only slowly released it when needed.
Cactus like to grow in arid desert. In the arid environment, cactus gradually formed its own unique drought resistance characteristics: the stem is thick and juicy, there are developed parenchyma cells, good at storing water; The epidermis of stem is covered by thick and hard wax or dense villi, so as to avoid and reduce sunlight and water evaporation. Cactus has huge root system, strong ability to absorb water, and is good at collecting trace water. In case of rainfall, it will grow many new roots on the surface and absorb a lot of water. The big root of cactus is protected by thick cork tissue, which can live tenaciously on the hot sand without drying out. Some cacti can live for hundreds of years.
仙人掌喜欢生长在干旱的沙漠里。 在干旱的环境中，仙人掌逐渐形成了自己独特的抗旱特征：茎肥厚多汁，有发达的薄壁组织细胞善于贮藏水分;茎的表皮由厚而硬的蜡质或生有密集的绒毛覆盖，从而避免和减少阳光照射，降低水分蒸发。仙人掌根系庞大，吸收水分的能力很强，善于收集微量的水分。一遇降雨，它就会在表层长出许多新根，大量吸水。仙人掌的大根有很厚的木栓组织保护，能在灼热的沙石上顽强生活而不会干死。 有些大仙人掌的寿命可达数百年。