Changes

[[Image:Ferns02.jpg|thumb|Tree ferns, probably ''Dicksonia antarctica'']]

[[Image:Ferns02.jpg|thumb|Tree ferns, probably ''Dicksonia antarctica'']]

Like the sporophytes of seed plants, those of ferns consist of:

Like the sporophytes of seed plants, those of ferns consist of:

* [[Plant stem|Stems]]: Most often

* [[Plant stem|Stems]]: Most often an underground creeping [[rhizome]], but sometimes an above-ground creeping [[stolon]] (e.g., [[Polypodiaceae]]), or an above-ground erect semi-woody trunk (e.g., [[Cyatheaceae]]) reaching up to 20 m in a few species (e.g., ''Cyathea brownii'' on [[Norfolk Island]] and ''Cyathea medullaris'' in [[New Zealand]]).

an underground creeping [[rhizome]], but sometimes an above-ground creeping [[stolon]] (e.g., [[Polypodiaceae]]), or an above-ground erect semi-woody trunk (e.g., [[Cyatheaceae]]) reaching up to 20 m in a few species (e.g., ''Cyathea brownii'' on [[Norfolk Island]] and ''Cyathea medullaris'' in [[New Zealand]]).

* [[Leaf]]: The [[green]], [[photosynthesis|photosynthetic]] part of the plant.  In ferns, it is often referred to as a [[frond]], but this is because of the historical division between people who study ferns and people who study seed plants, rather than because of differences in structure.  New leaves typically expand by the unrolling of a tight spiral called a crozier or [[fiddlehead]]. This uncurling of the leaf is termed [[circinate vernation]]. Leaves are divided into two types:

* [[Leaf]]: The [[green]], [[photosynthesis|photosynthetic]] part of the plant.  In ferns, it is often referred to as a [[frond]], but this is because of the historical division between people who study ferns and people who study seed plants, rather than because of differences in structure.  New leaves typically expand by the unrolling of a tight spiral called a crozier or [[fiddlehead]]. This uncurling of the leaf is termed [[circinate vernation]]. Leaves are divided into two types:

** Trophophyll: A leaf that does not produce spores, instead only producing sugars by photosynthesis. Analogous to the typical green leaves of seed plants.

** Trophophyll: A leaf that does not produce spores, instead only producing sugars by photosynthesis. Analogous to the typical green leaves of seed plants.