 All three are typically dioecious, although some "Ephedra" species exhibit monoecy.In contrast to the conifers, which have simple pollen strobili and compound seed strobili, gnetophytes have both compound pollen and seed strobili.The seed strobili of "Ephedra" and "Gnetum" are reduced, with "Ephedra" producing only two ovules per strobilus and "Gnetum" a single ovule.