Ferns (Filicopsida: all fern families), horsetails (Equisetaceae) and club mosses (Lycopodiaceae) are vascular *, non-flowering plants that do not produce seed (Maddison and Schulz 2004). All of these seedless, vascular plants have a life cycle separated into two distinct stages. The large plant, called the sporophyte (spore producing plant), produces spores by meiosis, the cell division process that creates sex cells. Cells produced by meiosis have only one copy of each gene (i.e. one set of chromosomes rather than two). These “haploid” spores germinate and produce the second life cycle stage called the gametophyte (gamete-producing). Gametophytes are either very small, green, moss-like plants, in the case of most ferns and horsetails, or underground tuber-like plants closely associated with, and dependent upon, specific types of mycorrhizal fungi, in the case of many club mosses. The gametophyte produces haploid sex cells (gametes: sperm and eggs) by ordinary cell division (mitosis). Sperm […]