bioRxiv · 2026-05-23
A key mechanism that lets flowering plants open their stomata wide — and thus grow faster and more productively — originated once, in the very first flowering plant ancestor, and has been present in all angiosperms ever since. This trait likely enabled the explosive success of flowering plants on Earth.
Mechanical advantage in stomatal opening was confirmed in 14 newly tested species spanning the earliest-diverging angiosperm lineages, bringing the total surveyed to at least 230 species across 85 families.
The trait is present in Amborella trichopoda, the single species considered sister to all other flowering plants, indicating it evolved once in the common ancestor of all angiosperms.
The researchers hypothesize that without this stomatal mechanical advantage, flowering plants could not have fully exploited their water-transport innovations — suggesting it was a key driver of angiosperm ecological dominance.
