How do plants reproduce from a stem?

Generally stem helps to provide mechanical support, conduction and display of various parts. some times it undergo some change to perform vegetative propagation. These are called stem modifications. These are of three types.
!. Aerial stems : Bulbils in Dioscorea, Agave, Globba, Oxalis.
Bulbils are modified storage vegetative or floral buds when get detached from the parent plant germinate into baby plant.
2. Sub-aerial stems : These are partially aerial and partially underground. these are of four types.
a) Runners : These are rooted at every node.
Hydrocotyle, Oxalis.
b)Stolons : Walking stems
Nerium, Rose
c) Suckers :
Chrysanthimum and Mentha
d) Off sets :
Pistia and eichhornia
3. Underground stems :These are of four types.
a) Rhizome : It propagates horizontally below the ground.
Ziniber officinalis, Curcuma longa, Musa paradisica, Canna indica.
b) Corm : It propagates vertically below the ground.
Colocasia, Amorphophallus.
c) Stem tuber : It is formed at the tips of underground lateral branches and is propagated through "eyes." Each eye represent a node, scar of reduced scale leaf and an axillary bud.
Solanum tuberosa, Helianthes tuberosa, Stachyosa tubifera.
d) Bulb : Stem is reduced to a disc and produces group of adventitious roots and fleshy leaves in opposite directiions
Allium cepa and Allium sativa.