植物种子的寿命差别很大，一些短命种子，像柳树之类，在露天之下只要一个星期就会丧失发芽能力。更有甚者，一种沙漠植物“梭梭树”，一旦成熟，在自然条件下几小时之内就会死亡，不过，如果遇上一点点水，它将很快发芽、生根，转入新一轮的生长循环之中。 　　当然大部分种子 The life span of plant seeds varies greatly, and some short-lived seeds, such as willow, lose their ability to germinate for as long as a week under the open air. What is more, a desert plant called “Haloxylon ammodendron” will die within a matter of hours under natural conditions, but if it encounters a little bit of water, it will soon germinate, take root and switch to new A round of growth cycle. Of course most of the seeds