The apical portion of a * stamen , which produces the microspores or pollen grains. An anther normally comprises four * pollen sacs (but only two in the Malvaceae) arranged in two groups or lobes joined by the connective tissue to the filament. If the anther is attached to the filament on the dorsal surface allowing it to pivot it is called a versatile anther. If it is attached dorsally but there is no movement it is termed a dor-sifixed anther and if attached at the base it is a basifixed anther. The wall of the anther lobes consists of an outer epidermis below which is the * endothecium . This surrounds an inner nutritive layer or * tapetum . Within the cavity (loculus) of the lobes pollen mother cells undergo rheiosis to form tetrads of pollen grains. The individual pollen sacs are joined by zones of parenchyma tissue. Compare ovule . |
