Presence of Air Cavities in Pods of an Endemic Legume Crotalaria pusilla Dc. (Leguminosae, Papilionoideae)

The legume lineage evolved approximately 60 Mya in the region to the north of the Tethys Sea, a shallow stretch of salt water that separated the two main groups of land masses¹ . Since then legumes have adopted various mechanisms for dispersal and colonization, among which one of the probable methods is the diaspore (a dispersal unit consisting of a seed with additional tissues that assist dispersal). The papilionoid crown node is dated 58.6 Mya with further divergence into genistoid and dalbergoid, the former dated at 56.4 Mya (ref. 1). Since their divergence, both the lineages have adopted radically different approaches to life from their common ancestors. One of the approaches is seed dispersal, which plays a central role in ecology dynamics, thereby understanding and predicting the population and community change² . Understanding the convergent evolution of seed dispersal is a central question in evolutionary ecology, because dispersal traits are linked to plant survival strategies and are a reflection of the reproductive assurance theory³ .