Section of a tulip bulb: underground bulb of a tulip.
External envelope: outer layer of the bulb.
Fleshy leaf: fleshy part of the bulb.
Developing stem: primitive stage of the stem of the tulip.
Root: part of the bulb that absorbs nutrients.
Development of a lateral bud in the bulb: primitive stage of a bulb.
Early stage of a lateral bud: first stage of the bud within the axis of a leaf.