Question

Difference between corm and bulb?

Answer 1

Corm and bulb are underground stem modification. They help in storage of food to survive under extreme conditions. Stem provides structural support to the plant. They are modified into three main categories
1. Underground Modifications
2. Sub-aerial Modifications
3. Aerial Modifications.

Complete Answer:
Corms are extended underground stems that store nutrients for the plant during periods of inactivity or dormancy. They are spherical in shape with a flat base and develop vertically below the ground. They are basically the same as bulbs. In contrast to bulbs, corms are strong and don't have scales or fleshy leaves. Crocosmia, freesia are examples of corms.
A bulb is an underground stem with fleshy and scale-like layers encompassing a middle bud. The base of the bulb is composed of adventitious roots. The shoots of the bulbs are developed from the lateral buds and their leaves are functioned to store food. Leaves and flowers are produced from apical buds. Onion and garlic are examples of a bulb.
Differences between corm and bulb.

BULB	CORM
They are short stems with fleshy leaves or leaf bases.	They are round, underground storage organs consisting of a swollen stem base covered with scale leaves
Functioned to store food	Swollen stem bases
Bulbs are composed of scales.	Corms are smooth modified stems.
It is a condensed underground shoot	Corm is a condensed underground stem
Leaf bases is functioned to store food	Stem is functioned to store food
Anion and tulip are the examples of bulb	Gladiolus, freesia are the examples of corm
Buds are borne internally	Buds are borne externally

Notes:
Underground modifications of stem include
1. Rhizome
2. Bulb
3. Corm
4. Tuber
Sub-aerial modifications of stem include
1. Runner
2. Colon
3. Sucker
4. Offset
Aerial Modifications include
1. Stem Tendrils
2. Thorns
3. Phylloclade
4. Cladodes
5. Bulbils
6. Thalamus