Here I provide you some examples of modified stems:
Bulb: discoid stems that have a single apical bud surrounded by numerous cataphiles, and in their part I have adventitious roots. Its function is the reserve.
Tuber: They are portions of stems with irregular growth, which forms tuberosities due to the large accumulation of reserve substances.
Cladodes: are flattened stems, very thick, green leaves look alike and have photosynthetic function.
Stem tendrils: they are filamentous stems, which can be rolled up so that the plant can climb grasped of various objects, which is useful when the plant needs to look for the greatest possible luminosity, especially in areas where shadows predominate.
Phylloclades: Stems sheet form with limited growth, like a leaf, green and photosynthetic color.