Cycads ' are seed plants typically characterized by a stout and woody (ligneous) trunk

Trunk (botany)

In botany, trunk refers to the main wooden axis of a tree that supports the branches and is supported by and directly attached to the roots. The trunk is covered by the bark, which is an important diagnostic feature in tree identification, and which often differs markedly from the bottom of the...

 with a crown

Crown (botany)

The crown of a plant refers to the totality of the plant's aboveground parts, including stems, leaves, and reproductive structures. A plant canopy consists of one or more plant crowns growing in a given area....

 of large, hard and stiff, evergreen

Evergreen

In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...

 leaves. They usually have pinnate

Pinnate

Pinnate is a term used to describe feather-like or multi-divided features arising from both sides of a common axis in plant or animal structures, and comes from the Latin word pinna meaning "feather", "wing", or "fin". A similar term is pectinate, which refers to a comb-like arrangement of parts...

 leaves. The individual plants are either all male or all female (dioecious

Dioecious

Dioecy is the property of a group of biological organisms that have males and females, but not members that have organs of both sexes at the same time. I.e., those whose individual members can usually produce only one type of gamete; each individual organism is thus distinctly female or male...

). Cycads vary in size from having a trunk that is only a few centimeters tall to trunks up to several meters tall. They typically grow very slowly and live very long, with some specimen

Specimen

A specimen is a portion/quantity of material for use in testing, examination, or study.BiologyA laboratory specimen is an individual animal, part of an animal, a plant, part of a plant, or a microorganism, used as a representative to study the properties of the whole population of that species or...

s known to be as much as 1,000 years old.