Ferns

Ferns were the first plants with vessels, so, unlike mosses, they can grow large: tree ferns reach ten metres or more. A fern's stem usually runs underground, and from it rise long-stalked leaves, called fronds, that unroll from a tight coil. Ferns have no flowers and no seeds. The brown or orange dots under a frond are clusters of spore cases; a spore that lands somewhere damp grows into a new fern. In Iran ferns grow wild in the damp forests of the north.