Protected by leaves that undergo changes in color and consistency, is that it stores mineral reserves, which are essential during the rest period before the first buds appear. And it is the kind of "potato" that determines the division between the bulbous, which can be played by corm, tuber, rhizome or bulb.
The corm is compact and has no layers. Inside are not seen leaves and flowers. The Gladiolus is a corm, like Freesia.
In tubers, the main feature is the presence of roots throughout the bulb (a bulb and a corm have real roots only at the base). Examples: the tuberous Begonia and Dahlia.
The rhizome is a thickened stem that grows horizontally underground, developing several gems.
Amaryllis: In the bulb there is already a miniature flower. Plant this bulb in a pot and leave it in place with good lighting, and protect them from the sun at midday.
Narcissus: true bulb, increases in volume every year, until reaching its maximum size, are produced then other bulbs that bind to the largest. These divisions can be separated and saved for another plant. The ideal time to reap the daffodil bulbs is when their leaves fall off naturally. By separating the smaller bulbs bulb not do the operation in the sunlight, so they do not dry. It is suitable for cultivation in cold regions of the country.
Lily: In the spring, plant your bulbs in the garden. To reproduce by bulbils, tiny bulbs that appear in the leaf axils.