Fixation of anthers:

 It is the attachment of the filament to the anthers.

1. The anthers is said to be adnate when the filament runs up the whole length in between the anther lobes e.g. Buttercup.
2. Basifixed- when filament is attached to the base of anther e.g. Brassica (Sarson), Raphanus et.
3. Dorsifixed- when filament is attached to the back of anther e.g. Passiflora.
4. Versatile- When filament is attached to the back of the anther and the anther can swing freely in the air e.g. grasses.