Question

In Erythrina indica and Dolichos lablab, the leaves are
A.Unipinnate
B.Bipinnate
C.Tripinate
D.Trifoliate

Answer 1

Pinnation is the arrangement of feather-like characteristics which appears from both the sides of a common axis. It is the arrangement of leaflets, veins, lobes etc. The leaflets are attached with the addition of petioles known as rachis.

Complete answer:
-Unipinnate: It is a type of compound leaf with a row of leaflets arranged through each side of the common rachis. The example of the unipinnate leaf is Azadirachta indica.
-Bipinnate: It is a type of pinnate leaf in which the leaflets are more subdivided into a pinnate fashion. It is characterized by the presence of secondary rachis on the primary rachis. They contain double pinnate and are known as bipinnate. The bipinnate leaves are present in the trees of honey locust, silk trees etc.
-Tripinnate: In the tripinnate type of leaf the single leaflets in the unipinnate leaves is replaced by the bipinnate leaf. These leaves contain two leaf blades attached to the petioles at a single point. The example of the tripinnate leaf is Mongira oleifera.
-Trifoliate: It is a type of compound leaves which is characterized by the leaf is divided into three leaflets. The Erythrina indica and Dolichos lablab have trifoliate leaves.
Hence, the correct answer is D.

Note: Erythrina indica is a medium-sized spiny, deciduous tree normally growing to 6-9 m long trees. Dolichos lablab is commonly found in Africa and it is cultivated more in the tropical region. It is the only species found in the monotypic genus.