Dear student.
Plants normally do not reproduce by the process of fragmentation. But there are some plants which develop adventitious plantlets on their leaves, bulbils and turions, which drop off and grows into an independent plant. Ex: piggyback plant.
Fragmentation is a form of asexual reproduction in which an entirely new organism is formed from a fragment of the parent. It occurs in multicellular organisms, whose body organization is fairly simple such as annelids, starfish, fungi, lichens, and some algae such as Spirogyra.The filaments of Spirogyra, upon maturation, break into small pieces or fragments, which grow into new individuals.
Regards.