Greenhouse Tour 2 Cycads Cycads, while resembling palms and ferns stand alone as a unique group of coned, seed-bearing plants. Today they are limited to tropical and subtropical regions of the world and consist of 185 species in 11 different genera. A unique evolutionary feature of cycads, shared only by the Ginkgo tree, is that they have motile sperm known as spermatozoids. Humankind has used cycads for a variety of purposes.
Many cultures use the trunks and seeds as a source of starch.
Within the last hundred years, commercial mills produced nearly 15 tons of Zamia food starch per day along southern Florida's Miami River. African tribes prepare beer from the central pith of Encephalartos sp. Ornamental use of cycads in recent times has created an underground market for the illegal collection and sale of large plants. There are only single colonies left of many species, and many countries have passed strict legislation in order to try and preserve these rare and fascinating plants. Zamia skinneri Native to shady understory forests of Costa Rica, Nicaragua, and Panama, and named for George Ure Skinner, a 19th-century plantsman.