Tapetum begins to degenerate at the early stage of free microspore, producing lots of ubisch bodies, and it becomes completely degenerated at anther dehiscence.

• 小孢子发育早期绒毡层开始降解并分泌形成大量乌氏体，花药开裂时绒毡层完全消失，剩下少量乌氏体。