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The stamen (pl.: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium.^[1]

Morphology and terminology

A stamen typically consists of a stalk called the filament and an anther which contains microsporangia. Most commonly anthers are two-lobed (each lobe is termed a locule) and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The size of anthers differs greatly, from a tiny fraction of a millimeter in Wolfia spp up to five inches (13 centimeters) in Canna iridiflora and Strelitzia nicolai.

The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in Canna species or as many as 3,482 stamens which have been counted in the saguaro (Carnegiea gigantea).^[2] The androecium in various species of plants forms a great variety of patterns, some of them highly complex.^[3]^[4]^[5]^[6] It generally surrounds the gynoecium and is surrounded by the perianth. A few members of the family Triuridaceae, particularly Lacandonia schismatica and Lacandonia brasiliana,^[7] along with a few species of Trithuria (family Hydatellaceae) are exceptional in that their gynoecia surround their androecia.

*Hippeastrum* flowers showing stamens above the style (with its terminal stigma)

Etymology

Stamen is the Latin word meaning "thread" (originally thread of the warp, in weaving).^[8]
Filament derives from classical Latin filum, meaning "thread"^[8]
Anther derives from French anthère,^[9] from classical Latin anthera, meaning "medicine extracted from the flower"^[10]^[11] in turn from Ancient Greek ἀνθηρά (anthērá),^[9]^[11] feminine of ἀνθηρός (anthērós) meaning "flowery",^[12] from ἄνθος^[9] (ánthos) meaning "flower"^[12]
Androecium (pl.: androecia) derives from Ancient Greek ἀνήρ (anḗr) meaning "man",^[12] and οἶκος (oîkos) meaning "house" or "chamber/room".^[12]

Variation in morphology

Depending on the species of plant, some or all of the stamens in a flower may be attached to the petals or to the floral axis. They also may be free-standing or fused to one another in many different ways, including fusion of some but not all stamens. The filaments may be fused and the anthers free, or the filaments free and the anthers fused. Rather than there being two locules, one locule of a stamen may fail to develop, or alternatively the two locules may merge late in development to give a single locule.^[13] Extreme cases of stamen fusion occur in some species of Cyclanthera in the family Cucurbitaceae and in section Cyclanthera of genus Phyllanthus (family Euphorbiaceae) where the stamens form a ring around the gynoecium, with a single locule.^[14] Plants having a single stamen are referred to as "monandrous."

Pollen production

A typical anther contains four microsporangia. The microsporangia form sacs or pockets (locules) in the anther (anther sacs or pollen sacs). The two separate locules on each side of an anther may fuse into a single locule. Each microsporangium is lined with a nutritive tissue layer called the tapetum and initially contains diploid pollen mother cells. These undergo meiosis to form haploid spores. The spores may remain attached to each other in a tetrad or separate after meiosis. Each microspore then divides mitotically to form an immature microgametophyte called a pollen grain.

The pollen is eventually released when the anther forms openings (dehisces). These may consist of longitudinal slits, pores, as in the heath family (Ericaceae), or by valves, as in the barberry family (Berberidaceae). In some plants, notably members of Orchidaceae and Asclepiadoideae, the pollen remains in masses called pollinia, which are adapted to attach to particular pollinating agents such as birds or insects. More commonly, mature pollen grains separate and are dispensed by wind or water, pollinating insects, birds or other pollination vectors.

Pollen of angiosperms must be transported to the stigma, the receptive surface of the carpel, of a compatible flower, for successful pollination to occur. After arriving, the pollen grain (an immature microgametophyte) typically completes its development. It may grow a pollen tube and undergo mitosis to produce two sperm nuclei.

Sexual reproduction in plants

In the typical flower (that is, in the majority of flowering plant species) each flower has both carpels and stamens. In some species, however, the flowers are unisexual with only carpels or stamens. (monoecious = both types of flowers found on the same plant; dioecious = the two types of flower found only on different plants). A flower with only stamens is called androecious. A flower with only carpels is called gynoecious.

A pistil consists of one or more carpels. A flower with functional stamens but no functional pistil is called a staminate flower, or (inaccurately) a male flower. A flower with a functional pistil but no functional stamens is called a pistillate flower, or (inaccurately) a female flower.^[15]

An abortive or rudimentary stamen is called a staminodium or staminode, such as in Scrophularia nodosa.

The carpels and stamens of orchids are fused into a column.^[16] The top part of the column is formed by the anther, which is covered by an anther cap.

Terminology

Stamen

Stamens can also be adnate (fused or joined from more than one whorl):

epipetalous: adnate to the corolla
epiphyllous: adnate to undifferentiated tepals (as in many Liliaceae)

They can have different lengths from each other:

didymous: two equal pairs
didynamous: occurring in two pairs, a long pair and a shorter pair
tetradynamous: occurring as a set of six stamens with four long and two shorter ones

or respective to the rest of the flower (perianth):

exserted: extending beyond the corolla
included: not extending beyond the corolla

They may be arranged in one of two different patterns:

spiral; or
whorled: one or more discrete whorls (series)

They may be arranged, with respect to the petals:

diplostemonous: in two whorls, the outer alternating with the petals, while the inner is opposite the petals.
haplostemenous: having a single series of stamens, equal in number to the proper number of petals and alternating with them
obdiplostemonous: in two whorls, with twice the number of stamens as petals, the outer opposite the petals, inner opposite the sepals, e.g. Simaroubaceae (see diagram)

Connective

Where the connective is very small, or imperceptible, the anther lobes are close together, and the connective is referred to as discrete, e.g. Euphorbia pp., Adhatoda zeylanica. Where the connective separates the anther lobes, it is called divaricate, e.g. Tilia, Justicia gendarussa. The connective may also be a long and stalk-like, crosswise on the filament, this is a distractile connective, e.g. Salvia. The connective may also bear appendages, and is called appendiculate, e.g. Nerium odorum and some other species of Apocynaceae. In Nerium, the appendages are united as a staminal corona.

Filament

A column formed from the fusion of multiple filaments is known as an androphore. Stamens can be connate (fused or joined in the same whorl) as follows:

extrorse: anther dehiscence directed away from the centre of the flower. Cf. introrse, directed inwards, and latrorse towards the side.^[17]
monadelphous: fused into a single, compound structure
declinate: curving downwards, then up at the tip (also – declinate-descending)
diadelphous: joined partially into two androecial structures
pentadelphous: joined partially into five androecial structures
synandrous: only the anthers are connate (such as in the Asteraceae). The fused stamens are referred to as a synandrium.

Anther

Anther shapes are variously described by terms such as linear, rounded, sagittate, sinuous, or reniform.

The anther can be attached to the filament's connective in two ways:^[18]

basifixed: attached at its base to the filament
- pseudobasifixed: a somewhat misnomer configuration where connective tissue extends in a tube around the filament tip
dorsifixed: attached at its center to the filament, usually versatile (able to move)

Gallery

Scanning electron microscope image of Pentas lanceolata anthers, with pollen grains on surface
Lily stamens with prominent red anthers and white filaments
Calliandra surinamensis petalized stamens
Sterculia foetida stamens
Stamen of a Grevillea robusta
Commelina communis three different types of stamens

References

^ Beentje, Henk (2010). The Kew Plant Glossary. Richmond, Surrey: Royal Botanic Gardens, Kew. ISBN 978-1-84246-422-9., p. 10
^ Charles E. Bessey in SCIENCE Vol. 40 (November 6, 1914) p. 680.
^ Sattler, R. 1973. Organogenesis of Flowers. A Photographic Text-Atlas. University of Toronto Press. ISBN 0-8020-1864-5.
^ Sattler, R. 1988. A dynamic multidimensional approach to floral morphology. In: Leins, P., Tucker, S. C. and Endress, P. (eds) Aspects of Floral Development. J. Cramer, Berlin, pp. 1-6. ISBN 3-443-50011-0
^ Greyson, R. I. 1994. The Development of Flowers. Oxford University Press. ISBN 0-19-506688-X.
^ Leins, P. and Erbar, C. 2010. Flower and Fruit. Schweizerbart Science Publishers, Stuttgart. ISBN 978-3-510-65261-7.
^ Rudell, Paula J.; et al. (February 4, 2016). "Inside-out Flowers of Lacandonia braziliana...etc". PeerJ. 4: e1653. doi:10.7717/peerj.1653. PMC 4748704. PMID 26870611.
^ ^a ^b Lewis, C.T. & Short, C. (1879). A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary. Oxford: Clarendon Press.
^ ^a ^b ^c Klein, E. (1971). A comprehensive etymological dictionary of the English language. Dealing with the origin of words and their sense development thus illustration the history of civilization and culture. Amsterdam: Elsevier Science B.V.
^ Siebenhaar, F.J. (1850). Terminologisches Wörterbuch der medicinischen Wissenschaften. (Zweite Auflage). Leipzig: Arnoldische Buchhandlung.
^ ^a ^b Saalfeld, G.A.E.A. (1884). Tensaurus Italograecus. Ausführliches historisch-kritisches Wörterbuch der Griechischen Lehn- und Fremdwörter im Lateinischen. Wien: Druck und Verlag von Carl Gerold's Sohn, Buchhändler der Kaiserl. Akademie der Wissenschaften.
^ ^a ^b ^c ^d Liddell, H.G. & Scott, R. (1940). A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie. Oxford: Clarendon Press.
^ Goebel, K.E.v. (1969) [1905]. Organography of plants, especially of the Archegoniatae and Spermaphyta. Vol. Part 2 Special organography. New York: Hofner publishing company. pages 553–555
^ Rendle, A.B. (1925). The Classification of Flowering Plants. Cambridge University Press. p. 624. ISBN 9780521060578. cyclanthera.
^ Encyclopædia Britannica.com
^ Carr, Gerald (30 October 2005). "Flowering Plant Families". Vascular Plant Family. University of Hawaii Botany Department. Retrieved 3 August 2022.
^ William G. D'Arcy, Richard C. Keating (eds.) The Anther: Form, Function, and Phylogeny. Cambridge University Press, 1996 ISBN 9780521480635
^ Hickey, M.; King, C. (1997). Common Families of Flowering Plants. Cambridge University Press. ISBN 9780521576093.

Bibliography

Rendle, Alfred Barton (1911). "Flower" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 10 (11th ed.). Cambridge University Press. pp. 553–573.
Simpson, Michael G. (2011). "Androecium". Plant Systematics. Academic Press. p. 371. ISBN 978-0-08-051404-8. Retrieved 6 February 2014.
Weberling, Focko (1992). "1.5 The Androecium". Morphology of Flowers and Inflorescences (trans. Richard J. Pankhurst). CUP Archive. p. 93. ISBN 0-521-43832-2. Retrieved 8 February 2014.
"Obdiplostemony (obdiplostemonous)". Glossary for Vascular Plants. The William & Lynda Steere Herbarium, New York Botanical Garden. Retrieved 20 September 2019.

External links

[Been10-1] Beentje, Henk (2010). The Kew Plant Glossary. Richmond, Surrey: Royal Botanic Gardens, Kew. ISBN 978-1-84246-422-9., p. 10

[2] Charles E. Bessey in SCIENCE Vol. 40 (November 6, 1914) p. 680.

[3] Sattler, R. 1973. Organogenesis of Flowers. A Photographic Text-Atlas. University of Toronto Press. ISBN 0-8020-1864-5.

[4] Sattler, R. 1988. A dynamic multidimensional approach to floral morphology. In: Leins, P., Tucker, S. C. and Endress, P. (eds) Aspects of Floral Development. J. Cramer, Berlin, pp. 1-6. ISBN 3-443-50011-0

[5] Greyson, R. I. 1994. The Development of Flowers. Oxford University Press. ISBN 0-19-506688-X.

[6] Leins, P. and Erbar, C. 2010. Flower and Fruit. Schweizerbart Science Publishers, Stuttgart. ISBN 978-3-510-65261-7.

[7] Rudell, Paula J.; et al. (February 4, 2016). "Inside-out Flowers of Lacandonia braziliana...etc". PeerJ. 4: e1653. doi:10.7717/peerj.1653. PMC 4748704. PMID 26870611.

[Lewis_&_Short-8] Lewis, C.T. & Short, C. (1879). A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary. Oxford: Clarendon Press.

[Klein1971-9] Klein, E. (1971). A comprehensive etymological dictionary of the English language. Dealing with the origin of words and their sense development thus illustration the history of civilization and culture. Amsterdam: Elsevier Science B.V.

[Siebenhaar1850-10] Siebenhaar, F.J. (1850). Terminologisches Wörterbuch der medicinischen Wissenschaften. (Zweite Auflage). Leipzig: Arnoldische Buchhandlung.

[Saalfeld1884-11] Saalfeld, G.A.E.A. (1884). Tensaurus Italograecus. Ausführliches historisch-kritisches Wörterbuch der Griechischen Lehn- und Fremdwörter im Lateinischen. Wien: Druck und Verlag von Carl Gerold's Sohn, Buchhändler der Kaiserl. Akademie der Wissenschaften.

[Liddell_&_Scott-12] Liddell, H.G. & Scott, R. (1940). A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie. Oxford: Clarendon Press.

[13] Goebel, K.E.v. (1969) [1905]. Organography of plants, especially of the Archegoniatae and Spermaphyta. Vol. Part 2 Special organography. New York: Hofner publishing company. pages 553–555

[14] Rendle, A.B. (1925). The Classification of Flowering Plants. Cambridge University Press. p. 624. ISBN 9780521060578. cyclanthera.

[Encyclopædia_Britannica.com-15] Encyclopædia Britannica.com

[16] Carr, Gerald (30 October 2005). "Flowering Plant Families". Vascular Plant Family. University of Hawaii Botany Department. Retrieved 3 August 2022.

[17] William G. D'Arcy, Richard C. Keating (eds.) The Anther: Form, Function, and Phylogeny. Cambridge University Press, 1996 ISBN 9780521480635

[18] Hickey, M.; King, C. (1997). Common Families of Flowering Plants. Cambridge University Press. ISBN 9780521576093.

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@@ Line 1: / Line 1: @@
+{{Short description|Male organs of a flower}}
-[[Image:Crateva_religiosa.jpg|thumb|right|250 px|Flower of the spider tree (Crateva religiosa) with its numerous conspicuous stamens]]
+{{About||the Bulgarian physician|Stamen Grigorov|the data visualization and cartography studio|Stamen Design|the structure in cryptogams|Antheridium}}
+[[File:Amaryllis stamens aka.jpg|thumb|right|250px|Stamens of a ''[[Hippeastrum]]'' with white filaments and prominent anthers carrying [[pollen]]]]
+The '''stamen''' ({{plural form}}: '''stamina''' or '''stamens''') is a part consisting of the male [[reproductive organ]]s of a flower. Collectively, the stamens form the '''androecium'''.<ref name=Been10>{{Citation |mode=cs1 |last=Beentje |first=Henk |year=2010 |title=The Kew Plant Glossary |location=Richmond, Surrey |publisher=[[Royal Botanic Gardens, Kew]] |isbn=978-1-84246-422-9 }}, p. 10</ref>
-The '''stamen''' is the male [[organ (anatomy)|organ]] of a [[flower]].
+{{Anchor|filament|anther|connective}}
-Typical flowers have six stamens inside a '''''perianth''''' (the ''[[petal]]s'' and ''[[sepal]]s'' together), arranged in a whorl around the [[pistil]]. But in some species there are many more than six present in a flower.  Collectively, the stamens are called '''androecium''' (from Greek ''andros oikia'': man's house). They are positioned just below the [[flower|gynoecium]].
+==Morphology and terminology==
-Each stamen consists of a thin stalk called a '''''filament''''' supporting an '''''anther''''' that contains the '''''[[sporangium|microsporangia]]'''''.
+{{Anchor|Filament}}
+{{Anchor|Anther}}
+[[File:Stamen (PSF).png|thumb|Diagram of stamen]]
+A stamen typically consists of a stalk called the '''filament''' and an '''anther''' which contains [[sporangium|microsporangia]]. Most commonly anthers are two-lobed (each lobe is termed a '''locule''') and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the [[Connective (botany)|'''connective''']], an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A [[pollen]] grain develops from a [[microspore]] in the microsporangium and contains the male [[gametophyte]]. The size of anthers differs greatly, from a tiny fraction of a millimeter in ''Wolfia'' spp up to five inches (13 centimeters) in  ''[[Canna iridiflora]]'' and ''[[Strelitzia nicolai]]''.
+The stamens in a flower are collectively called the '''androecium'''. The androecium can consist of as few as one-half stamen (i.e. a single [[locule]]) as in ''[[Canna (plant)|Canna]]'' species or as many as 3,482 stamens which have been counted in the [[saguaro]] (''Carnegiea gigantea'').<ref>Charles E. Bessey in SCIENCE Vol. 40 (November 6, 1914) p. 680.</ref> The androecium in various species of plants forms a great variety of patterns, some of them highly complex.<ref>Sattler, R. 1973. ''Organogenesis of Flowers. A Photographic Text-Atlas''. University of Toronto Press. {{ISBN|0-8020-1864-5}}.</ref><ref>Sattler, R. 1988. A dynamic multidimensional approach to floral morphology. In: Leins, P., Tucker, S. C. and Endress, P. (eds) ''Aspects of Floral Development''. J. Cramer, Berlin, pp. 1-6. {{ISBN|3-443-50011-0}}</ref><ref>Greyson, R. I. 1994. ''The Development of Flowers''. Oxford University Press. {{ISBN|0-19-506688-X}}.</ref><ref>Leins, P. and Erbar, C. 2010. ''Flower and Fruit''. Schweizerbart Science Publishers, Stuttgart. {{ISBN|978-3-510-65261-7}}.</ref> It generally surrounds the [[gynoecium]] and is surrounded by the [[perianth]]. A few members of the family [[Triuridaceae]], particularly ''[[Lacandonia schismatica]]'' and ''[[Lacandonia brasiliana]]'',<ref>{{cite journal | title=Inside-out Flowers of Lacandonia braziliana...etc | last= Rudell | first= Paula J. | journal=PeerJ |display-authors=etal | date= February 4, 2016 | volume=4 | pages=e1653 | doi=10.7717/peerj.1653 | pmid=26870611 | pmc=4748704 | doi-access= free }}</ref> along with a few species of  ''[[Trithuria]]'' (family [[Hydatellaceae]]) are  exceptional in that their gynoecia surround their androecia.
-[[Haploid]] [[pollen]]&mdash;the male [[gamete]] cells of a [[flowering plant]]&mdash;are produced by the ''microsporangia''.
+[[File:Hippeastrum-1.jpg|thumb|''Hippeastrum'' flowers showing stamens above the style (with its terminal stigma)]]
+[[File:Closeup of Lilium 'Stargazer' (the 'Stargazer lily').jpg|thumb|Closeup of stamens and pistil of ''Lilium'' 'Stargazer']]
+==Etymology==
-The anthers are bilocular. i.e. they have two locules. Each locule contains a microsporangium. The tissue between the the locules and the cells is called the '''connective'''.
+* '''Stamen''' is the [[Latin]] word meaning "thread" (originally thread of the [[warp (weaving)|warp]], in weaving).<ref name="Lewis & Short"/>
+* '''Filament''' derives from [[classical Latin]] [[wikt:filum|filum]], meaning "thread"<ref name="Lewis & Short">Lewis, C.T. & Short, C. (1879). ''A Latin dictionary founded on Andrews' edition of Freund's Latin dictionary.'' Oxford: Clarendon Press.</ref>
+* '''Anther''' derives from French [[wikt:anthère|anthère]],<ref name="Klein1971">Klein, E. (1971). ''A comprehensive etymological dictionary of the English language. Dealing with the origin of words and their sense development thus illustration the history of civilization and culture.'' Amsterdam: Elsevier Science B.V.</ref> from classical Latin [[wikt:anthera|anthera]], meaning "medicine extracted from the flower"<ref name="Siebenhaar1850">Siebenhaar, F.J. (1850). ''Terminologisches Wörterbuch der medicinischen Wissenschaften.'' (Zweite Auflage). Leipzig: Arnoldische Buchhandlung.</ref><ref name="Saalfeld1884">Saalfeld, G.A.E.A. (1884). ''Tensaurus Italograecus. Ausführliches historisch-kritisches Wörterbuch der Griechischen Lehn- und Fremdwörter im Lateinischen.'' Wien: Druck und Verlag von Carl Gerold's Sohn, Buchhändler der Kaiserl. Akademie der Wissenschaften.</ref>  in turn from [[Ancient Greek]] [[wikt:ἀνθηρά|ἀνθηρά]] ({{transliteration|grc|anthērá}}),<ref name="Klein1971"/><ref name="Saalfeld1884"/> feminine of [[wikt:ἀνθηρός|ἀνθηρός]] ({{transliteration|grc|anthērós}}) meaning "flowery",<ref name="Liddell & Scott">Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press.</ref> from [[wikt:ἄνθος|ἄνθος]]<ref name="Klein1971"/> ({{transliteration|grc|ánthos}}) meaning "flower"<ref name="Liddell & Scott"/>
+* '''Androecium''' ({{plural form}}: '''androecia''') derives from [[Ancient Greek]] [[wikt:ἀνήρ|ἀνήρ]] ({{transliteration|grc|anḗr}}) meaning "man",<ref name="Liddell & Scott"/> and [[wikt:οἶκος|οἶκος]] ({{transliteration|grc|oîkos}}) meaning "house" or "chamber/room".<ref name="Liddell & Scott"/>
+==Variation in morphology==
-In an immature, unopened bud, the filaments are still short. Their function is then to transport nutrients to the developing pollen. They start to lengthen when the bud opens.
+[[File:Mature flower diagram.svg|thumb|right|Stamens, with distal anther attached to the filament stalk, in context of floral anatomy]]
+Depending on the species of plant, some or all of the stamens in a flower may be attached to the petals or to the [[floral axis]]. They also may be free-standing or fused to one another in many different ways, including fusion of some but not all stamens. The filaments may be fused and the anthers free, or the filaments free and the anthers fused. Rather than there being two locules, one locule of a stamen may fail to develop, or alternatively the two locules may merge late in development to give a single locule.<ref>{{cite book|author=Goebel, K.E.v.|orig-year=1905|year=1969|volume=Part 2 Special organography|title=Organography of plants, especially of the Archegoniatae and Spermaphyta|publisher=Hofner publishing company|location=New York|url=https://archive.org/details/organographyofpl02goeb}} pages 553–555</ref> Extreme cases of stamen fusion occur in some species of ''[[Cyclanthera]]'' in the family [[Cucurbitaceae]] and in section ''Cyclanthera'' of genus ''[[Phyllanthus]]'' (family [[Euphorbiaceae]]) where the stamens form a ring around the gynoecium, with a single locule.<ref>{{cite book|author=Rendle, A.B.|year=1925|title=The Classification of Flowering Plants|publisher=Cambridge University Press|isbn=9780521060578|url=https://archive.org/details/classificationof0002rend|url-access=registration|page=[https://archive.org/details/classificationof0002rend/page/624 624]|quote=cyclanthera.}}</ref> Plants having a single stamen are referred to as "monandrous."
+[[File:Antera Lilium.jpg|thumb|right|Cross section of a ''Lilium'' stamen, with four locules surrounded by the tapetum]]
-The anther can be attached to the filament in two ways :
-*basifixed : attached at its base to the filament; this gives rise to a '''longitudinal dehiscence''' (opening along its length to release pollen).
-*versatile : attached at its center to the filament; pollen is then relased through pores ('''poricidal dehiscence''').
-[[Image:Penta anther.jpg|thumb|right|250 px|Scanning electron microscope image of Penta lanceolata anthers, with pollen grains on surface]]
-Stamens can be '''connate''' (fused or joined in the same whorl) :
-* '''monadelphous''' : fused into a single, compound structure
-* '''diadelphous''' : joined partially tinto two androecial structures.
-* '''synantherous''' : only the anthers are connate (such as in the [[Asteraceae]])
+==Pollen production==
-Stamens can also be '''adnate''' (fused or joined from more than one whorl)
+A typical anther contains four microsporangia. The ''microsporangia'' form sacs or pockets (''locules'') in the anther (anther sacs or pollen sacs). The two separate locules on each side of an anther may fuse into a single locule. Each microsporangium is lined with a nutritive tissue layer called the ''tapetum'' and initially contains diploid pollen mother cells. These undergo meiosis to form [[haploid]] spores. The spores may remain attached to each other in a tetrad or separate after meiosis. Each microspore then divides mitotically to form an immature [[Gametophyte|microgametophyte]] called a [[Pollen|pollen grain]].
-*'''epipetalous''' : adnate to the [[corolla]].
-* '''didynamous''' : occurring in two pairs of different length.
-* '''tetradynamos''' : occurring as a set of six filaments with two shorter ones.
-* '''exserted''' : extending beyonf the coralla.
-* '''included''' : not extending from the coralla.
+The pollen is eventually released when the anther forms openings ([[dehiscence (botany)#Anther dehiscence|dehisces]]). These may consist of longitudinal slits, pores, as in the [[Erica (plant)|heath]] family ([[Ericaceae]]), or by valves, as in the [[barberry]] family ([[Berberidaceae]]). In some plants, notably members of [[Orchidaceae]] and [[Asclepiadoideae]], the pollen remains in masses called [[Pollinium|pollinia]], which are adapted to attach to particular pollinating agents such as birds or insects. More commonly, mature pollen grains separate and are dispensed by wind or water, pollinating insects, birds or other pollination vectors.
-In the typical flower (that is, the majority of flowering plant species) each  flower has both a [[pistil]] and stamens. The bisexual plants are called hermaphrodites or perfect flowers.
+Pollen of [[angiosperm]]s must be transported to the [[Stigma (botany)|stigma]], the receptive surface of the [[carpel]], of a compatible flower, for successful [[pollination]] to occur. After arriving, the pollen grain (an immature microgametophyte) typically completes its development. It may grow a pollen tube and undergo mitosis to produce two sperm nuclei.
-However, in some species the flowers are unisexual with only either male or female parts ('''monoecious''' = on the same plant; '''dioecious''' = on different plants). A flower with only male reproductive parts is called '''androecious'''. A flower with only female reproductive parts is called '''gynoecious'''
+== Sexual reproduction in plants ==
-A flower having only functional stamens is called a '''staminate flower'''.
+{{Main article|Sexual reproduction in plants}}
+[[File:Phalaenopsis orchid-Stipe.jpg|thumb|right|Stamen with [[pollinia]] and its anther cap. ''[[Phalaenopsis]]'' orchid.]]
+In the typical flower (that is, in the majority of flowering plant species) each flower has both '''[[carpel]]s''' and '''stamens'''. In some species, however, the flowers are unisexual with only carpels or stamens. ('''[[monoecious]]''' = both types of flowers found on the same plant; '''[[dioecious]]''' = the two types of flower found only on different plants). A flower with only stamens is called '''androecious'''. A flower with only carpels is called '''gynoecious'''.
+A '''pistil''' consists of one or more carpels. A flower with functional stamens but no functional pistil is called a '''staminate flower''', or (inaccurately) a male flower. A flower with a functional pistil but no functional stamens is called a '''pistillate flower''', or (inaccurately) a female flower.<ref name="Encyclopædia Britannica.com">[http://www.britannica.com/EBchecked/topic/461851/pistillate-flower Encyclopædia Britannica.com]</ref>
-An abortive or rudimentary stamen is called a '''staminodium''', such as in ''[[Scrophularia nodosa]]''.
+An abortive or rudimentary stamen is called a '''staminodium''' or '''[[staminode]]''', such as in ''[[Scrophularia|Scrophularia nodosa]]''.
-The pistil and the stamens of [[orchid]]s are fused into a [[column (botany)|column]]. The top part of the column is formed by the anther. This is covered by an '''anther cap'''
+The [[Gynoecium|carpels]] and stamens of [[orchid]]s are fused into a [[column (botany)|column]].<ref>{{Cite web |url=http://www.botany.hawaii.edu/faculty/carr/orchid.htm |title=Flowering Plant Families |last=Carr |first=Gerald |date=30 October 2005 |website=Vascular Plant Family |publisher=University of Hawaii Botany Department |access-date=3 August 2022}}</ref> The top part of the column is formed by the anther, which is covered by an '''anther cap'''.
+== Terminology ==
-[[Image:WheatFlower3.JPG|thumb|left|250px|Flowers of wheat at anthesis showing stamens]]
+;Stamen
+Stamens can also be '''adnate''' (fused or joined from more than one whorl):
+* '''epipetalous''': adnate to the [[Corolla (flower)|corolla]]
+* '''epiphyllous''': adnate to undifferentiated [[tepal]]s (as in many [[Liliaceae]])
+They can have different lengths from each other:
+* '''didymous''': two equal pairs
+* '''didynamous''': occurring in two pairs, a long pair and a shorter pair
+* '''tetradynamous''': occurring as a set of six stamens with four long and two shorter ones
+or respective to the rest of the flower ([[perianth]]):
+* '''exserted''': extending beyond the corolla
+* '''included''': not extending beyond the corolla
+They may be arranged in one of two different patterns:
+* '''spiral'''; or
+* '''whorled''': one or more discrete whorls (series)
+They may be arranged, with respect to the [[petals]]:
+* '''diplostemonous''': in two [[Whorl (botany)|whorls]], the outer alternating with the petals, while the inner is opposite the petals.
+* '''haplostemenous''': having a single series of stamens, equal in number to the proper number of petals and alternating with them
+* '''obdiplostemonous''': in two whorls, with twice the number of stamens as petals, the outer opposite the petals, inner opposite the sepals, e.g. [[Simaroubaceae]] (''see [[#Obdiplostemony|diagram]]'')
+;Connective
+Where the connective is very small, or imperceptible, the anther lobes are close together, and the connective is referred to as '''discrete''', e.g. ''[[Euphorbia]]'' pp., ''[[Adhatoda zeylanica]]''. Where the connective separates the anther lobes, it is called '''divaricate''', e.g. ''[[Tilia]]'', ''[[Justicia gendarussa]]''. The connective may also be a long and stalk-like, crosswise on the filament, this is a '''distractile''' connective, e.g. ''[[Salvia]]''. The connective may also bear appendages, and is called '''appendiculate''', e.g. ''[[Nerium odorum]]'' and some other species of [[Apocynaceae]]. In ''Nerium'', the appendages are united as a staminal corona.
+;Filament
-[[Category:Botany]]
+A column formed from the fusion of multiple filaments is known as an '''androphore'''. Stamens can be '''connate''' (fused or joined in the same whorl) as follows:
-[[es:Estambre]]
+* '''extrorse''': anther [[Dehiscence (botany)|dehiscence]] directed away from the centre of the flower. Cf. '''introrse''', directed inwards, and '''latrorse''' towards the side.<ref>[https://books.google.com/books?id=SuUVYOFCTwYC William G. D'Arcy, Richard C. Keating (eds.) The Anther: Form, Function, and Phylogeny. Cambridge University Press, 1996] {{ISBN|9780521480635}}</ref>
-[[eo:Stameno]]
+* '''monadelphous''': fused into a single, compound structure
-[[de:Staubblatt]]
+* '''declinate''': curving downwards, then up at the tip (also – declinate-descending)
-[[fr:Étamine]]
+* '''diadelphous''': joined partially into two androecial structures
-[[nl:Meeldraad]]
+* '''pentadelphous''': joined partially into five androecial structures
-[[pt:Androceu]]
+* '''synandrous''': only the anthers are connate (such as in the [[Asteraceae]]). The fused stamens are referred to as a '''synandrium'''.
+;Anther
+Anther shapes are variously described by terms such as '''linear''', '''rounded''', '''sagittate''', '''sinuous''', or '''reniform'''.
+The anther can be attached to the filament's connective in two ways:<ref>{{cite book|author1=Hickey, M. |author2=King, C. |year=1997|title=Common Families of Flowering Plants|publisher=Cambridge University Press|isbn=9780521576093|url=https://books.google.com/books?id=nhQQho64fxYC&q=basifixed+poricidal+dehiscence&pg=PA16}}</ref>
+* '''basifixed''': attached at its base to the filament
+** '''pseudobasifixed''': a somewhat misnomer configuration where connective tissue extends in a tube around the filament tip
+* '''dorsifixed''': attached at its center to the filament, usually '''versatile''' (able to move)
+== Gallery ==
+{{gallery|align=center|mode=packed
+|File:Penta anther.jpg|Scanning electron microscope image of ''[[Pentas lanceolata]]'' anthers, with pollen grains on surface
+|File:Lily stamens.jpg|[[Lily]] stamens with prominent red anthers and white filaments
+|File:蘇利南合歡 Calliandra surinamensis 20210529152746 02.jpg|''[[Calliandra surinamensis]]'' petalized stamens
+|File:香蘋婆 Sterculia foetida 20210409164154 01.jpg|''[[Sterculia foetida]]'' stamens
+|File:銀樺 Grevillea robusta 20210411152016 14.jpg|Stamen of a ''[[Grevillea robusta]]''
+|File:鴨跖草 Commelina communis 20210824095446 03.jpg|''[[Commelina communis]]'' three different types of stamens
+}}
+== References ==
+{{Reflist}}
+== Bibliography ==
+{{refbegin}}
+* {{cite EB1911 |wstitle=Flower |volume=10 |pages=553–573 |first=Alfred Barton |last=Rendle}}
+* {{cite book |chapter-url=https://books.google.com/books?id=dj8KRImgyf4C&pg=PA371 |first1=Michael G. |last1=Simpson |title=Plant Systematics |chapter=Androecium|page=371|publisher=Academic Press |year=2011 |isbn=978-0-08-051404-8 |access-date=6 February 2014 }}
+* {{cite book|last=Weberling|first=Focko|title=Morphology of Flowers and Inflorescences (trans. Richard J. Pankhurst)|year=1992|publisher=CUP Archive|isbn=0-521-43832-2|page=93|chapter-url=https://books.google.com/books?id=-ZlOAAAAIAAJ&pg=PA87|access-date=8 February 2014|chapter=1.5 The Androecium}}
+* {{anchor|Obdiplostemony}}{{cite web |title= Obdiplostemony (obdiplostemonous)|url= http://sweetgum.nybg.org/science/glossary/glossary-details/?irn=1103|website= Glossary for Vascular Plants|publisher=The William & Lynda Steere Herbarium, [[New York Botanical Garden]] |access-date=20 September 2019|ref={{harvid|NYBG|2019}}}}
+{{refend}}
+==External links==
+{{wiktionary|Androecium|Anther|Filament|Gynoecium|Stamen}}
+{{Commons and category|Stamen and anther|Stamens}}
+{{botany}}
+{{Authority control}}
+[[Category:Plant anatomy]]
+[[Category:Plant morphology]]
+[[Category:Plant sexuality]]
+[[Category:Plant reproductive system]]
+[[Category:Pollination]]