LAND PLANT CHARACTERISTICS. #3. “Third, they retain the fertilized egg (i.e. the zygote) within the archegonium, wherein the sporophyte embryo is nurtured and protected. The retention of the diploid embryo within the archegonium is the reason why the land plants are called ‘embryophytes’ and why the older literature referred to them as the Archegoniatae.”
http://onlinelibrary.wiley.com/doi/10.1111/j.1469-8137.2009.03054.x/full