In botany, a bulb is a short underground stem with fleshy leaves or leaf bases[1] that function as food storage organs during dormancy.
The bulb's leaf bases, also known as scales, generally do not support leaves, but contain food reserves to enable the plant to survive adverse conditions.
Non-tunicate bulbs, such as Lilium and Fritillaria species, lack the protective tunic and have looser scales.
[4] Plants that form underground storage organs, including bulbs as well as tubers and corms, are called geophytes.
Some epiphytic orchids (family Orchidaceae) form above-ground storage organs called pseudobulbs, that superficially resemble bulbs.