Compound Leaf Notes
Leaves are an essential vegetative component of plants. Through photosynthesis, they produce food for the plant and are attached to the stem at nodes. They originate from shoot apical meristems, while branches grow from the axillary bud found in the axil of the leaf.
#Types of Leaves
Leaves are divided into two main types based on the division of the lamina:
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Simple Leaves - Simple leaves have a single, undivided lamina, such as a banana leaf. Even if the lamina is cut, it will not reach the midrib, as is the case with a maple leaf. They do not have leaflets.
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Compound Leaves - Compound leaves are composed of multiple leaflets, which are divisions of the leaf lamina.
Let’s Dive Deep into Compound Leaves!
#Compound Leaf Types
When a single leaf is divided into multiple leaflets, it is called a compound leaf. The incision of the lamina reaches the midrib and divides the leaf into multiple leaflets. It is important to note that leaflets do not have axillary buds in their axils like leaves do. Axillary buds are present in the petiole of both simple and compound leaves, but not in the leaflets.
Compound leaves are of two types:
- Pinnately Compound Leaves - Leaves of this type consist of leaflets that are arranged along a common axis, known as the rachis, which is analogous to the midrib. Each leaflet may also have its own stalk. For example, the leaves of the Neem tree.
Pinnately compound leaves can be unipinnate, bipinnate, tripinnate, etc.
The primary rachis of a bipinnate compound leaf is branched, with leaflets present on the secondary rachis.
- Palmately Compound Leaves - In these types of leaves, the leaflets are attached to the petiole at a single point, as seen in plants such as the Silk Cotton.
Palmately compound leaves can be classified into unifoliate, bifoliate, trifoliate, etc. depending on the number of leaflets present.
