Cycads were more varied and more widely distributed during the Mesozoic Period. The cycads that exist today are slowly dwindling in number due to the endangerment of their habitats, slow growth rate, and reproductive rate. They are restricted to tropic and subtropic areas. Although they are really unrelated to any other group of plants, Cycads are grouped with the gymnosperms. They have been linked to palms and ferns because of their leaf development.
Cycads are basic woody plants with roots, a stem, leaves, and reproductive cones.
The main roots of are thick, fleshy, and tuberous. These possess contractile tissues that regulate the level of the stem in the ground. All Cycads have special roots that grow upright and branch. These are coralloid roots. Coralloid roots contain the symbiotic cyanobacteria Anabaena to aid in nitrogen fixation.