This sap may contain toxic chemicals which cause severe poisoning, as well as carcinogenic effects. The sap from this tree has been used by South Americans as an arrow poison for numbing fish. It has also been used to poison criminals. Cycads Cycads are among the most primitive living seed plants. Their 9 genera represent the remnants of an extensive flora that was dominated by Cycads in the early Mesozoic, about 200 million years ago, when dinosaurs roamed the earth.
Cycads are native to tropical and subtropical regions of the world.
A male cone on a Cycas revoluta . Two drugs, vincablastine and vincacristine, which have been developed from this species are effective in treating certain types of leukemia. Washington is the most planted cultivar and prized for its large fruits, which easily separate from the peel and into sections. Many common citrus types may have come from this type of mutation by the mother plant, including seedless oranges, grapefruits, and limes. The yellow bananas we buy in the grocery store are similar to the bananas growing on this plant.