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One of the planet's most amazing plants is the pine tree. Why? The pine tree itself is a sporophyte, but it has gametophytes in its cones. The tree's reproductive stages can also be found in the pine cone: the spores, eggs, sperm, zygotes, and embryos. Each of the tiny scales of the cone contains is made up of sporangia that help produce the spores by meiosis. Those spores then produce gametophytes inside the cone. The male gametophyte, the pollen grain, breaks away from the pollen and is carried by the wind to the female cones. Each of the female cones carry two ovules on each scale-each ovule being surrounded by an integument. Once pollination has occurred, the scales then grow together which seals up the cone and within that cone the gametophytes continue to produce gametes. About a year after pollination, fertilization occurs and the ovule becomes a seed. In other words, the pine cone is an essential part of how pine trees reproduce!
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Source: Class Notes-Chapter 17: Plants, Fungi, and the Colonization of Land
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