The embryos produce an exceptionally long Suspensor which thrusts the Embryo proper to the opposite end of the Megagametophyte. The Embryo literally grows backwards. The Integument matures to become the Seed Coat . This is usually hard and dry . Some Species develop winged extensions which assist wind dispersal.
Animals also eat the seeds which are very nutritious and rich in oil and carbohydrates.
Indigenous people in the Western states valued pine seeds and made them a regular part of their diet. Some seed coats are particularly durable and their seeds can survive in the seed bank for years . The hypocotyl elongates and the root protrudes from the seed. The cotyledons enlarge and remain inside the megagametophyte for some time during germination. Experiments have shown that seedling growth is directly related to the period of time the cotyledons are in contact with the Megagametophyte.