The Structure of a Bulb Plant

Main Bulb Parts

• Bulbs are broken down into five types of storage structures. Several leaf bases growing close together beneath the soil line comprise true bulbs. True bulbs have five main parts: a basal plate, a flattened area at the bulb's bottom from which roots grow; fleshy scales that are primary nutrient storage units; a tunic or skin-like covering that protects the fleshy scales; a shoot consisting of a developing flower; and leaf buds and lateral buds. The bulb contains a tiny preformed flower known as the flower primordium.

Tunicate Bulbs

• True bulbs are divided into tunicate bulbs and imbricate bulbs, affecting how the plants propagate. Tunicate bulbs have the paper-like covering or tunic that protects fleshy scales from drying and other injury. Tulips, daffodils and hyacinths are tunicate bulbs.

Imbricate Bulbs

• Imbricate bulbs do not have tunics protecting the fleshy scales. They must be kept constantly moist before planting so their scales do not dry out. Lilies are imbricate bulbs.