How do you distinguish between hypogeal germination and epigeal germination? What is the role of cotyledons and the endosperm in the germination of seed?

Dear student,

Details of two types of germination are as follow:

1.  Epigeal germination: In this case, the cotyledons are lifted above the ground, and they act as the first leaves as a result of the rapid elongation of the hypocotyl. It takes place in seeds such as castor, cotton, sunflower, etc.

2.  Hypogeal germination: In this case, the cotyledons remain inside the soil and the epicotyl elongates and pushes the plumule above. It takes place in seeds such as pea, maize, mango, etc.

Following figures will illustrate the difference clearly

Cotyledon is an important part of the seed and helps in its germination. They are part of embryo within seed and store nutrients in them. These are the first leaves produced by plants but are not true leaves.  They feed plant till true leaves develop and begin photosynthesis.
Endosperm is the tissue that surrounds, stores food and provide nourishment to the embryo in an angiosperm seed.

Hope this information will clear your doubts about the topic.
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