Stamen

The stamen is the male Organ of a Flower . Each stamen generally has a stalk called the '''filament''', and, on top of the filament, an ''' Anther '''. The anther is usually composed of four pollen sacs, which are called '' Microsporangia ''. The development of the ''microsporangia'' and the contained Haploid Spore s (called Pollen-grains ) is closely comparable with that of the microsporangia in Gymnosperm s or heterosporous Fern s. The pollen is set free by the opening (''dehiscence'') of the anther, generally by means of longitudinal slits, but sometimes by pores, as in the Heath family ( Ericaceae ), or by valves, as in the Barberry family ( Berberidaceae ). It is then dropped, or carried by some external agent — wind, water or some member of the Animal Kingdom — onto the receptive surface of the '' Carpel '' of the same or another flower, which is thus Pollinated . Typical flowers have six stamens inside a ''perianth'' (the '''''''. The anthers are bilocular, i.e. they have two locules. Each locule contains a microsporangium. The tissue between the locules and the cells is called the '''connective'''. In an immature, unopened flower Bud , the filaments are still short. Their function is then to transport Nutrient s to the developing pollen. They start to lengthen once the bud opens. 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 released through pores (poricidal dehiscence). Stamens can be connate (fused or joined in the same whorl): monadelphous : fused into a single, compound structure diadelphous : joined partially into two androecial structures synantherous : only the anthers are connate (such as in the Asteraceae ) Stamens can also be adnate (fused or joined from more than one whorl): 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 beyond the corolla included : not extending from the corolla. PLANT SEXUALITY Main article In the typical flower (that is, the majority of flowering plant species) each flower has both a pistil and '''stamens'''. Bisexual plants are named Hermaphrodites or perfect flowers. In some species, however, 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'''. A flower having only functional stamens is called a staminate flower. An abortive or rudimentary stamen is called a staminodium, such as in '' Scrophularia Nodosa ''. The pistil and the stamens of Orchid s are fused into a Column . The top part of the column is formed by the anther. This is covered by an anther cap.
	Image:WheatFlower3JPGFlowers Of	"http://wwwinformationdelightinfo/encyclopedia/entry/Vrhbosna/wheat" class="copylinks">Wheat at anthesis showing stamens Like all Grass es ( Poaceae ), wheat is wind-pollinated
	Image:Daylily Stamens Dry 01v2jpgStamens Of A ''	"http://wwwinformationdelightinfo/encyclopedia/entry/Vrhbosna/daylily" class="copylinks">Daylily '' (''Hemerocallis''), thickly covered in pollen
	Image:Albizia Julibrissin 'Rosea' Flower DetailjpgFlowers Of The "silk Tree" (''	"http://wwwinformationdelightinfo/encyclopedia/entry/Vrhbosna/Albizia_julibrissin" class="copylinks">Albizia Julibrissin '') have many long thread-like stamens

Information About

Stamen