A bulb's an underground vertical shoot that's modified leaves (or thickened leaf bases) that're used as food storage organs by a dormant plant. A bulb's leaf bases generally don't support leaves, but contain food reserves to enable the plant to survive adverse conditions. The leaf bases may resemble scales, or they may overlap and surround the center of the bulb as with the onion. A modified stem forms the base of the bulb, and plant growth occurs from this basal plate. Roots emerge from the… (More on Bulb)