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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 ...
An anther and its filament together form a typical (or filantherous) stamen, part of the male floral organ. The typical anther is bilocular, i.e. it consists of two thecae. Each theca contains two microsporangia, also known as pollen sacs. The microsporangia produce the microspores, which for seed plants are known as pollen grains.
If the anther is cut perpendicular to its axis, it is observed that each anther contains one or two pollen sacs extending along its entire length. [18] [14] After the maturation of the pollen grains, dehiscence or opening of the anther occurs to let the pollen out. The tissue responsible is called endothecium.
The tube simply soaks up nutrients from the female nucellus and grows in two stages. The pollen tube is highly branched and grows on the female sporophyte tissues. First, it grows the main tube followed by a more spherical tip at the end to allow the sperm to burst near the archegonia. [18]
The anther produces pollen grains which contain the male gametophytes that produce sperm nuclei. For pollination to occur, pollen grains must attach to the stigma of the female reproductive structure ( carpel ), where the female gametophytes are located within ovules enclose within the ovary .
The female counterpart to the antheridium in cryptogams is the archegonium, and in flowering plants is the gynoecium. An antheridium typically consists of sterile cells and spermatogenous tissue. The sterile cells may form a central support structure or surround the spermatogenous tissue as a protective jacket.
A pistil typically consists of an expanded basal portion called an ovary, an elongated section called a style and an apical structure called a stigma that receives pollen. The ovary (from Latin ovum, meaning egg) is the enlarged basal portion which contains placentas, ridges of tissue bearing one or more ovules (integumented megasporangia). The ...
A megasporocyte inside a megasporangium or ovule undergoes meiosis, producing four megaspores. Only one is a functional megaspore whereas the others stay dysfunctional or degenerate. The megaspore undergoes several mitotic divisions to develop into a female gametophyte (for example the seven-cell/eight-nuclei embryo sac in flowering plants).