The endothecium contains fibrous bands and callose bands. At some places callose bands and fibrous thickenings are absent. These places are called _______

At some places in the endothecium callose bands and fibrous thickenings are absent which are called stomium. Endothecium becomes hygroscopic in nature due to presence of fibrous thickening. Endothecium helps in dehiscence of anther.