1. (fibrous layer) In angiosperms, the layer of cells lying beneath the epidermis of the wall of the anther. As the anther matures, thickenings often develop in the cell walls of the endothecium, probably aiding dehiscence.
2. In Bryophyta, the inner layer of cells in the young sporophyte.
"endothecium." A Dictionary of Plant Sciences. . Encyclopedia.com. (October 17, 2018). http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/endothecium
"endothecium." A Dictionary of Plant Sciences. . Retrieved October 17, 2018 from Encyclopedia.com: http://www.encyclopedia.com/science/dictionaries-thesauruses-pictures-and-press-releases/endothecium