苏铁属在生物分类学上是苏铁目中苏铁科的唯一属。苏铁，又称为铁树、凤尾铁、凤尾蕉，属于苏铁科。苏铁类植物是地球上现存最古老的种子植物，源于古生代，迄今为止已有2.8亿年的历史。到侏罗纪的时候，苏铁类植物已遍及全球，成为恐龙的主要食物。目前世界上苏铁属有90种 ，其中大多数是在过去1200万年中的某个时候形成的 。分布南自澳洲及东南亚一带，北至中国南部和日本南部，其中光果苏铁亦分布在东非及马达加斯加。

苏铁“Cycas”一词源于希腊文的椰子树名，苏铁类植物常被误认为棕榈树或是蕨类植物。

苏铁类植物的精子有许多鞭毛，现生的种子植物中很少有这样的现象。

Cycas is the type genus and the only genus recognised in the family Cycadaceae. About 113 species are accepted . Cycas circinalis, a species endemic to India was the first cycad species to be described and was the type of the generic name, Cycas. The best-known Cycas species is Cycas revoluta. The Cycas is a very ancient genus of trees. The group achieved its maximum diversity in the Jurassic and Cretaceous periods, when it was distributed almost worldwide. At the end of the Cretaceous, when the non-avian dinosaurs became extinct, so did most of the cycas in the Northern Hemisphere.