Encephalartos arenarius (South Africa)
CYCADS are gymnosperms, as are conifers. They are tropical and subtropical shrubs or small trees, which often resemble short, wicked, palms, some with a pineapple-like cone. Cycads have been around for over 200 million years, from even before dinosaur times. Cycads are dioecious, having male and female reproductive organs on separate plants, so there's no way to tell whether a plant is male or female until they cone, which can be 50 or 60 years! Intro to cycads provides information about the history and evolution of these plants.
Cycads may be the most primitive gymnosperms in existence. The word "gymnosperm" comes from the Greek word gymnospermos, meaning "naked seeds." Gymnosperm seeds develop either on the surface of scale or leaf-like appendages of cones, or at the end of short stalks.
Conifers are the most numerous species within the gymnosperms. According to one estimate, there are 947 species of gymnosperms, of which 289 species are cycads and 589 species are conifers.
The Gymnosperm Database is the best reference I have found about conifers and gymnosperm taxonomy. It has exhaustive information and scientific and technical details about all known conifers, and doesn't shrink from touching on gray areas and conflicting research.
The Cycad Pages also provides a diagram showing cycad taxonomy and evolutionary relationships.
Encephalartos senticosus with massive terminal seed cone
Burrawang, Macrozamia communis
(New South Wales, Australia)
Encephalartos trispinosus (Eastern Cape Province, South Africa)
Lepidozamia peroffskyana (Australia)