南美洲有一种奇特的植物——卷柏。说它奇特,是因为它会走。卷柏的生存需要充足的水分,当水分不足时,它就会自己把根从土壤里拔出来,让整个身体缩卷成一个圆球状,只要稍有一点儿风,它就会随风在地面上滚动。一旦滚到水分充足的地方,圆球就会迅速打开,根重新钻到土壤里,暂时安居下来。当水分又一次不足时,它会继续游走,寻找充足的水源。难道卷柏不走就生存不了吗?为此,一位植物学家对卷柏做了这样一个实验:用 South America has a peculiar plant - Selaginella. It is peculiar because it will go. The survival of Selaginella requires adequate water, when the water is not enough, it will pull out the root itself from the soil, so that the entire body shrink into a round ball, as long as a little bit of wind, it will wind on the ground Scroll up. Once you get to ample water, the spheres will open quickly and the roots will re-drown in the soil and settle for the time being. When the water is insufficient again, it will continue to walk, looking for sufficient water. Is it possible for a cypress not to survive? For this reason, a botanist made such an experiment with cypress: