Many plants grow from bulbs. The onion is a common example of a bulb. If you look at the bottom of an onion you can see a ring of fibrous roots. This marks the position of the stem. The brown skin covering the onion is made from leaves which are adapted to protect the inside from harsh conditions. If you peel away these dry brown leaves you will see the white fleshy leaves which contain stored food.

The stem is disc-shaped and the leaves grow upwards from it. Between the leaves there are buds attached to the stem. They are capable of growing into new bulbs.

Many plants grow from bulbs. Most of them contain substances which are poisonous to us but they can be eaten by other animals.

The bulb remains underground throughout a plant's life. When conditions are favourable the bulb sends up leaves and a shoot with flowers on it. The leaves make food which is stored in the bulb. This stored food is used to make the leaves and flowers grow in the following year.