Riverweeds (Podostemaceae) are one of a kind among angiosperms owing to their deviant ecological, morphological and embryological features. Podostemaceae is well-known for rare occurrences of pollen grains as dyads. However, little is known about the development of pollen in a dyad. This paper highlights the key developmental events of dyad pollen in one of the endemic taxa of riverweeds (Polypleurum munnarense) through anatomical and ultrastructural studies. The study shows that the pollen in the species are acalymate, tricolpate and are connected through cytomictic channels. These channels are open during the initial stages of development. By mitosis I stage, the channels are completely obliterated due to deposition of the orbicular material. Pollen wall possesses a multi-layered microechinate exine consisting of a continuous tectum except in the colpus region, granular infratectum and a foot-layer. The dyads disperse at bi-celled stage and their wall retracts from the colpus regions, showing harmomegathic movements, that are aided by the granular infratectum of the exine. X-ray spectral analysis revealed the presence of signaling molecules in granular microechinate orbicules and pollenkitt, indicating their possible involvement in pollen development. Most of the features of pollen development recorded in the study seem to be adaptive in countering rapid temperature fluctuations that the plant experiences in its partially submerged habitat during flowering, and thus help it in its reproductive endeavours.