Remembrance of plants past

Editorial https://doi.org/10.1038/s41477-026-02322-8 Remembrance of plants past Check for updates The timescales on which plants operate are both much shorter and much longer than those on which we function. All we can observe are the traces they leave behind. “Time present and time past Are both perhaps present in time future, And time future contained in time past. If all time is eternally present All time is unredeemable.” —T. S. Eliot, Burnt Norton T ime is a very slippery concept. We all have an essential feeling of time and its passage, but as with so much ‘common sense’, it does not stand up to scientific scrutiny. Einstein, with his theory of relativity, thoroughly debunked the idea of an absolute universal time, showing that it was intimately connected to the observer’s viewpoint and that there was no way to define whether two events happened at the same time or even which came first. Meanwhile, others espouse the philosophy of ‘presentism’ (poetically described at the beginning of Eliot’s Four Quartets) — that the only reality is the infinitesimally brief present, the past being a construct of memory and the future that of imagination. It might seem that this has little to do with plant biology, lying more in the realms of philosophy or theoretical physics, but we are constantly attempting to reconstruct the dynamic processes of nature from static data, a tangible memory of the past. Arguably, the longest-scale memory of life comes in the form of fossils. Palaeontology is not without its challenges, especially when nature plants dealing with plants, as they possess few hard tissues, making conditions for good preservation vanishingly rare. As a result, the fossil record for the early evolution of plants is woefully incomplete. In all likelihood, this lies behind what Charles Darwin described as an ‘abominable mystery’ in a letter to Joseph Hooker: the sudden abundance and diversity of flowering plant fossils, particularly dicots, from the late Creta ceous era and their absence before this time. Since Darwin’s time, we have become more comfortable with the idea that evolution does not always proceed at a constant — slow — pace. Even so, it can seem surprising that there are so few, if any, uncontroversial fossils of angiosperms from the early Cretaceous or Jurassic eras. Of course, plants do have some hard and therefore more easily preserved tissues, specifically pollen. Pollen fossils have been discovered from an earlier age than fossils of more complete plants, but interpretation of fossil pollen in isolation is not straightforward. Paradoxically, we might know more about the evolution of marine algae in the Ordovician than we do about their land-living descendants several hundred million years later1. Fossil ‘memory’ can be clear and detailed, but it is very forgetful. The other botanical memory we have that stretches back into geological time is the DNA in the cells of living plants. While there is a direct line of descent from the genomes contained in the nuclei, mitochondria and chloroplasts of modern plants to those of their common ancestor and beyond, they have not come to us as faithfully preserved as fossils. Instead, they are handed down as in the children’s game of whispers, in which a simple phrase becomes corrupted by repeated cycles of hearing and retelling through a chain of individuals. Distortions of the genetic message accumulate more slowly in organelles than in the nucleus, owing to the absence of recombination during cell division. However, by combining a phylogeny of plastids from the majority of current plant families with time constraints derived from well-dated fossils, the origin of angiosperms has been placed somewhere in the Triassic, more than 200 million years ago2. This intriguingly corresponds with the age of some angiosperm-like pollen grains from around 245 million years ago3. The memory of genomes is also used to chart the more recent evolution of plant groups, as in the study of the nuclear genomes of water lilies published in this issue4. Plants also retain memories of the times in which they have lived. This is particularly true for trees, whose concentric growth circles in their trunks can be used to trace back climatic conditions over thousands of years5, especially when in association with fossilized wood6. Even the most up-to-date video imaging techniques used in cell biology are static slices of events that are already in the past, albeit separated by sufficiently small gaps in time as to capture some of the dynamics of the system; more time-lapse animation than present experience. On even shorter timescales, the ultrafast processes of photosynthesis must be captured by the electromagnetic ripples they produce. Nonetheless, our only tool to prepare for times future is to interrogate times past as preserved in the memories of time present. Published online: 22 May 2026 References 1. Liu, L. et al. Nat. Plants 11, 1116–1126 (2025). 2. Li, H. T. et al. Nat. Plants 5, 461–470 (2019). 3. Hochuli, P. A. & Feist-Burkhardt, S. Front. Plant Sci. 4, 344 (2013). 4. Zhang, J. et al. Nat. Plants https://doi.org/10.1038/ s41477-026-02281-0 (2026). 5. Opała-Owczarek, M. et al. Nat. Commun. 16, 11665 (2025). 6. Schubert, B. A. et al. Sci. Rep. 14, 17189 (2024). Volume 12 | May 2026 | 899 | 899  (...truncated)