Antherocephyta evolved from a common ancestor with the Hepatophyta, although much later in time. The hornwort gametophyte has archegonia and antheridia embedded in the thallus, possibly for greater protection. Unlike other nonvascular plants, the hornwort sporophyte continues to divide through its lifetime [Speer 1995]. This is an evolutionary advantage because it produces more spores. Hornworts also have stomata allowing them to regulate gas exchange. Hornworts are different from other plants in that they have one single large chloroplast per cell rather than many small ones. This may provide the small plant a better way of photosynthesizing.

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Nonvascular Plants

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