Types of leaves

There are mainly two types of leaves as follows,

Compound leaves are those in which the leaf blade or lamina is divided into a number of segments known as leaflets or pinnae.
Compound leaf Compound leaves are those in which the leaf blade or lamina is divided into a number of segments known as leaflets or pinnae.
e.g. Gulmohar, Acacia

Types of compound leaves

compound leaves, types of leaves

In this type, the leaflets are present laterally on a common axis called the rachis, which represents the mid-rib of the leaf.

A pinnately compound leaf bearing the leaflets directly on the archives. e.g. Tamarind, Cassia.

Paripinnate – A unipinnate leaf with an even number of leaflets. e.g. Cassia, Tamarind.

Imparipinnate – A unipinnate leaf with an odd number of leaflets. e.g. Rose.

Paripinnate leaves

Imparipinnate leaves

A twice pinnate compound leaf i.e. the midrib produces secondary axes on which the leaflets are borne. e.g. Acacia, Mimosa pudica.

Bipinnate compound leaf

All the leaflets of the palmetely compound leave are attached at a common point. i.e. at the tip of the petiole, like Fingers of the palm.

There are five types of palmately compound leaves –

Unifoliate – A single leaflet is articulated to the petiole. e.g. Citrus.
Bifoliate – Two leaflets are articulated to the petiole. e.g. Pithecolobium, Prinsepia innate.
Trifoliate – Three leaflets are articulated to the petiolate. e.g. Bel.
Quadrifoliate – Four leaflets are articulated to the petiole, e.g. Marsilea.
Multifoliate – Five leaflets are articulated to the petiole e.g. Ipomoea, Bombax.

A leaf without-petiole is called sessile. e.g. Calotropis.

A leaf with a petiole is called a petiolate. e.g. Hibiscus.