Conifers (gymnosperms) differ from grasses (angiosperms) in the formation of endosperm before fertilisation. In gymnosperms, as endosperm is formed before fertilisation, thus it is a haploid tissue. While in angiosperms endosperm is formed as a result of double fertilisation (triple fusion) and is a triploid tissue(3n). In both angiosperms and gymnosperms, the seeds are produced from ovules. Xylem trachieds and pollen tube formation are also common in both classes.