Diversity: 

The living Cycadophyta, represent the remnants of a once global taxon. They flourished during the Jurassic period when Dinosaurs ruled. The Mesozoic has been called the "Age of the Cycads" due to their abundance. They are sometimes called living fossils because extant plants are indistinguishable from certain fossils.

They can be found in Tropical and Subtropical regions of the world. There is only one species, Zamia pumila found on the Mainland in Southern Florida. This species is also present on many Caribbean Islands, including Cuba & Puerto Rico. Several species grow in Central America and Mexico. Species of Cycas are found in the Pacific Islands and on Australia where there are several other genera. The Southern part of Africa is also a haven for several cycad genera.

Cycads rarely form the dominant vegetation. They can be locally abundant, especially as a shrubby understory or ground cover. One species (Zamia pseudoparasitica) is epiphytic. Many populations are small and isolated. They can occupy poor, xeric sites where other plants can't compete well. Some species are arborescent (tree-like) but they are extremely slow growing and resemble Tree Ferns because they lack internodal elongation. The trunk surface is clothed with leaf bases. They have large Pinnately Compound leaves that resemble fern fronds.

Some species are nearly extinct, and may be represented by one or two plants in botanical gardens. 

Large Cycas sp. Note the Large Pinnately Compound Leaves. Megasporophylls occupy the center. Several species of Cycas are commonly planted in Hawaii.

Stangeria: a rare Cycad from S. Africa: This is shrub-like in its habit.

Zamia pseudoparasitica an Epiphyte

Microcycas calocoma: an Arborescent cycad native to Cuba