The leaf has three parts: leaf base, lamina and petiole. The base is attached to the stem which bears the stipules. Leaf base is of various types such as pulvinate, sheathing, decurrent, etc.
In Trifolium, pulvinate type of leaf base (swollen leaf base) is found, it is also found in some leguminous plants. Petiole helps to hold the blade of leaf to sunlight. The petiole is a long thin, flexible stalk. Lamina, which is also called leaf blade is a broad green part of the leaf with vein and veinlets.