世界上的蕨类植物有1万多种,是孢子植物中的最庞大类群。一些种类只到脚踝那么高,但是有些高大的蕨类植物具有像树木一样的树干。不同于像藓类植物和苔类植物的这类更低等一些的植物,蕨类具有实根和茎。它们的叶,或称复叶,通常会分成小叶,这些使得它们具有蕨类的形态。大多数蕨类植物生长在潮湿环境下,也有一些为浮淡水生活。同其他孢子植物一样,它们通过释放孢子进行繁殖;此外,它们的生活周期包含了两种独立的植物形态。 There are over 10,000 species of ferns in the world and the largest group of spore plants. Some species are only as tall as ankles, but some tall ferns have tree-like trunks. Unlike lower plants of this class, such as mosses and moss, ferns have solid roots and stems. Their leaves, or the compound leaves, usually divide into leaflets, which make them fernlike. Most ferns grow in humid environments, and some live in the water of freshwater. Like other spore plants, they reproduce by releasing spores; in addition, their life cycle contains two distinct plant morphologies.