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In page Gametophyte:

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In heterosporous plants (water ferns, some lycophytes, as well as all gymnosperms and angiosperms), there are two distinct types of sporangia, each of which produces a single kind of spore that germinates to produce a single kind of gametophyte. However, not all heteromorphic gametophytes come from heterosporous plants. That is, some plants have distinct egg-producing and sperm-producing gametophytes, but these gametophytes develop from the same kind of spore inside the same sporangium; Sphaerocarpos is an example of such a plant.[citation needed]