View source for Biology:Sporophyll

[[File:Fern-frond-sori.jpg|thumb|right|The sporophyll of a fern. It is a fertile leaf bearing reproductive structures.]]
A '''sporophyll''' is a [[Biology:Leaf|leaf]] that bears sporangia. Both [[Biology:Microphylls and megaphylls|microphylls and megaphylls]] can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called '''megasporophylls''', or [[Biology:Microsporangia|microsporangia]] and are called '''microsporophylls'''. The overlap of the prefixes and roots makes these terms a particularly confusing subset of botanical nomenclature.

Sporophylls vary greatly in appearance and structure, and may or may not look similar to sterile leaves. Plants that produce sporophylls include:

''[[Biology:Alaria esculenta|Alaria esculenta]]'', a brown alga which shows sporophylls attached near the base of the alga.<ref>Dickson, Carola I. 1963. ''British Seaweeds''. The Kew Series.</ref>

[[Biology:Lycophyte|Lycophyte]]s, where sporophylls may be aggregated into [[Biology:Strobilus|strobili]] (''Selaginella'' and some ''Lycopodium'' and related genera) or distributed singly among sterile leaves (''[[Biology:Huperzia|Huperzia]]''). Sporangia are borne in the axil or on the adaxial surface of the sporophyll. In heterosporous members, megasporophylls and microsporophylls may be intermixed or separated in a variety of patterns.

[[Biology:Fern|Fern]]s, which may produce sporophylls that are similar to sterile fronds or that appear very different from sterile fronds. These may be non-photosynthetic and lack typical pinnae, e.g. ''[[Biology:Onoclea sensibilis|Onoclea sensibilis]]''.

[[Biology:Cycad|Cycad]]s produce strobili, both pollen-producing and seed-producing, that are composed of sporophylls. 

''[[Biology:Ginkgo|Ginkgo]]'' produces microsporophylls aggregated into a pollen strobilus. Ovules are not born on sporophylls {{Citation needed|reason=the structure that carries the seed and arillus of Ginko can and has been interpreted as a leave (This means that Ovules are in Ginko born on megasphorophylls), why should this be wrong now?|date=October 2017}}.

[[Biology:Gymnosperm|Gymnosperm]]s, like ''Ginkgo'' and cycads, produce microsporophylls, aggregated into pollen strobili. However, unlike these other groups, ovules are produced on cone scales, which are modified shoots rather than sporophylls.

Some plants do not produce sporophylls. Sporangia are produced directly on stems. ''[[Biology:Psilotum|Psilotum]]'' has been interpreted as producing sporangia (fused in a synangium) on the terminus of a stem. ''[[Biology:Equisetum|Equisetum]]'' always produce strobili, but the structures bearing sporangia (sporangiophores) have been interpreted as [[Biology:Aerial stem modification|modified stems]]. The sporangia, despite being recurved are interpreted as terminal. 

Gnetophytes produce both compound pollen and seed strobili.

==References==
* C.Michael Hogan. 2010. [http://www.eoearth.org/article/Fern ''Fern''. Encyclopedia of Earth. National council for Science and the Environment]. Washington, DC

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[[Category:Plant morphology]]
[[Category:Plant reproduction]]
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{{Sourceattribution|Sporophyll}}