Sporangium
Sporangium has been derived from modern Latin word “spora” means spores and classical Greek word “angeion” which means vessel. So, sac like structure, which develops spores as tetrad after meiosis of spore mother cell.
Spore: Reproductive unit of a plant body which upon germination to form a new plant body.

Sporangium
Types of Sporangium (Depending upon Organization with Position, Shape, Source)
Synangium |
Strobilus | Sorus |
Sporocarp |
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Present at apex of Branchlet also known as fertile telome. Trilocular, spherical / oval in shape. |
Depending upon source. It has two types: |
Group of sporangium in spherical form present at either adaxial or abaxial surface of megasporophylls. |
Ellipsoidal fruiting body containing with sporangia, present at the base of petiole of megaphyll. |
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For example Psilotum Rhynia |
Aggregation of Micro Sporophylls into compact cone like structure at terminal position of main stem. |
Aggregation of sporangiophore into compact cone like structure at terminal position of main stem. |
For example: -Adaxial surface of megasporophylls Polipodieceae, Eusporangiate |
For example: Marsilea Salvinia azolla |
Trilocular /three dimensional with oval or spherical shape structure, containing one sporangium in one locus, present at terminal position in each one locus, present at terminal position of branchlet od dichotomous sporophytic plant body. |
For Example: Lycopodium Selaginella
With respect to development Eusporangiate. |
For Example:
Equisetum
With respect to development is Eusporangiate. |
-Abaxial surface of megasporophylls Fern, Eusporangiate. |
With respect to development is leptosporangiate. |
With respect to development is eusporangiate. |
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Types of Sporangium
Depending upon presence and absence of sporangia
1: Sterile Leaf/Vegetative Leaf
Without sporangia
Depending upon chlorophyll it has two types
Types of photosynthetic leaves
2: Fertile leaf/Sporophylls/Reproductive leaf
Depending upon nature of leave
Homosporophyll
Micro- Homosporophyll |
Mega- Homosporophyll |
Simple leaf without leaflets |
Compound leaf without leaflets. |
Sessile leaf without petiole |
Pinnate leaf with rachis. |
Small in size as compared to stem |
Large in size as compared to stem. |
Sporangium with same size of spores, present at axial of leaf. |
Sporangium with same size of spores as sorus, present at either Adaxial or Abaxial surface of leaf. |
Present at terminal position of stem as strobilus |
For example:
Adiantum (marginal side) Pteris (middle position) Dryopteris (middle position) Pteridium (middle position) Polypodiaceae (Adaxial side) |
For example: lycopodium |
Heterosporophyll
Micro- Heterosporophyll |
Mega-Heterosporophyll |
Simple leaf without leaflets |
It is absent in pteridophytes. |
Sessile leaf without petiole |
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Small in size as compared to stem |
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Sporangium with different size of spores present in axial of leaf. |
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Present as cone at terminal position of stem. |
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For example: Selleginella |
Majority of pteridophytes show homosporus condition. All bryophytes show homosporus condition.
Homospory
The condition, in which sporophylls contains same size of sporangia is called as Homospory.
Phyllospory
The condition, in which there is presence of sporangia either at dorsal or ventral side leaf is known as Phyllospory. E.g. Polypodiaceae
Heterospory
The condition in which sporophylls contains different types of sporangia is called as Heterospory.
Stachiospory /Stachiosporous Condition
The condition in which there is presence of sporangia in axial of leaf and stem is known as Stachiospory /Stachiosporous condition. E.g. Selaginella, lycopodium.
Read also:- Female Cone Lecture