Gender Dimorphism in Plants

http://elparaiso.org/orchidata/ctsm_venezuela/index.htmhttp://www.pbs.org/wgbh/nova/orchid/gall_04.html
Once the national flower of Venezuela and still gracing the country's 500 bolivar note, Catasetum pileatum is highly esteemed by collectors even though its large flowers last only a few days. This unusual orchid produces flowers that are either male or female, not both, as in all other orchids. Male flowers of this species are colorful and variegated, while females are yellow-green and uniform in pattern. Besides Venezuela, C. pileatum is native to Colombia, Brazil, and Trinidad and Tobago.