The thorns protect the young plant from browsers, but they also break up the wind currents, so that the cactus is wrapped in still air, and evaporation of moisture from the stem is kept very low.

• 它的刺能保护植物本身免受动物啃食 还可阻隔吹过仙人掌的气流 所以它被一层 静止的空气保护着 大大减低了水份从茎部蒸发的机会