I am quite unfamiliar with everything that is in the slightest related to biology, so I am very sorry if this question does not meet your standards and is too basic.

Lately I am quite enjoying growing some plants from seed and watching them grow. Doing this I noticed that, at least for apples and tomatoes, the first 'pair of leaves' looks quite like different from the leaves following. Especially for the apple, the first two leaves look like from a completely different plant.

So just out of curiosity, is this a general phenomenon and how can it be explained, i.e. why do these plants do it?

Thank you in advance for any reference/ hint/ answer!


1 Answer 1


They are referred to as cotyledons (seed-leaves).

Apples as specified in the question are dicotyledons, they have two seed-leaves. Some other plants are monocotyledonous, i.e. just have a single seed leaf, thus:

Monocotyledon and dicotyledon shown at first growth.

User: Pengo, via Wikipedia CC BY-SA 3.0 2022.

The cotyledons are a part of the embryonic plant and whilst inside the seed capsule store energy in the form of starch (e.g. in oats and barley) and or fats/oils (e.g. in nuts). They are a distinct form from the mature leaves which grow as the plant matures.

They are also present in the seed prior to fertilisation, as distinct from true leaves which develop later after germination.


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