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| -theveins : are a like wrinkles or pipes running along the blade. They are really the vascular bundles coming from the stem throughout the petiole into the the surface of the blade. The central vein is called Midrib. The different patters they draw in different species is a trait used by botanists to distinguish a plant from the other. |
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-The margin is the rim or final limit of the blade. It can offer different forms:
Different types of margin
The petiole is the connexion of the stem to the blade. It is the channel for the vascular bundles to arrive to it. It can be short or long. Those leaves having a petiole, no matter how long it may be, are called petiolated .There are some leaves without petiole. In this case they are called stalkless or sessile.
A petiolated leaf and a stalkless one
TEST
Test what you have learned about the leaf, clicking what you think is the correct answer among the three different possibilities.
1)The extended part of the leaf is called:
- petiole
- edge
-blade
2) The central vein of the blade is called:
- margin
- midrib
- stem
3) The channels that distribute the sap or circulatory fluids along the leaf are called:
- veins
-tunnels
-roots
4) Choose the correct statement:
-all the leaves are petiolated.
-all the leaves have a blade.
-all the leaves are sessile.
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