Understanding the process of emersed to submersed and vice-versa - technical paper

[Art]

For those of you more scientifically minded and that want to understand the morphology of why and how aquarium plants transform from emersed form to submersed form, I found a paper for you. It's called "The ABA-mediated switch between submersed and emersed life-styles in aquatic macrophytes". It's pay-to-access unfortunately but it's not terribly expensive.

Here's a brief summary:

[F]resh-water plants evolved the adaptive mechanism of heterophylly, which enabled them to switch between a submersed and an emersed leaf morphology. The plant hormone abscisic acid (ABA) is a key factor of heterophylly induction in aquatic plants and is a major switch between a submersed and emersed life. The mechanisms of ABA signal perception and transduction appear to be conserved throughout the evolution of basal plants to angiosperms and from terrestrial to aquatic plants. This review summarizes the interplay of environmental factors that act through ABA to orchestrate adaptation of plants to their aquatic environment.