Secondary xylem contains vessels, as in angiosperms, although the homology of the vessels in the two phylum is in question. The female gametophyte often lacks organized archegonia. Male cone mostly compound, and associated with bracts. Fertilization occurs through pollen-tubes with two male nuclei. Double fertilization is recorded for some members of the phylum as in angiosperms, although the two are not exactly homologous.
Insect pollination is likely due to cone exudations .