Leaf venation in some species of genus Cassia L.

The morphology of leaves has not received sufficient attention in systematic studies of dicotyledons. The dicot leaves exhibit a wide range of venation pattern which is complex but could be used in taxonomy. The present study deals with venation pattern of 3 species of genus Cassia L. It showed two types of venations i.e., craspedodromous (Cassia roxburghii DC.) and semi-craspedodromous (Cassia fistula L. and Cassia siamea Lam.). The result showed leaf venation patterns, based on number of veins, position of secondary veins, course and vein islet number. This study emphasized taxonomic importance of venation and its usefulness in classification. Species specific variations have been recorded with respect to shape of leaf, leaf apex and base in general and venation pattern in particular. Authentication Key based on these variations has been formulated.