Plant Behaviour, Adaptive Plasticity and Evolution: Reassessing the Debate on Plant Intelligence

Plants have traditionally been regarded as passive organisms that simply respond to environmental conditions. However, recent research has shown that they can perceive a wide range of external signals, communicate through chemical and electrical pathways, modify their development according to changing environments, and retain physiological information from previous experiences. These discoveries have challenged traditional views of plant life and stimulated a growing interdisciplinary debate on concepts such as plant behaviour, adaptation, memory and intelligence. This review examines current evidence from plant biology together with perspectives from evolutionary theory and the philosophy of biology. Rather than asking whether plants are intelligent in the same sense as animals, the review explores how plant behaviour can be understood as the outcome of highly integrated and adaptive biological processes that do not require a nervous system. The review also discusses the conceptual and methodological challenges involved in applying cognitive terminology to plants and argues that plant research offers valuable insights into the evolution of complex adaptive systems. By integrating biological evidence with philosophical analysis, this review contributes to a broader and less anthropocentric understanding of living organisms.

For much of the history of Western biology, plants have been regarded as essentially passive organisms, incapable of behaviour in the sense attributed to animals. This conception stems from a long philosophical tradition which, beginning with Aristotle, has rigidly distinguished vegetative life from sensory and rational life. Within this hierarchy, the plant world was associated solely with the functions of nutrition, growth and reproduction, whilst behaviour, intentionality and perception were regarded as the prerogatives of animals. This paradigm was further reinforced by modern mechanistic thought. Descartes equated non-human organisms with biological automata, whilst nineteenth-century physiology interpreted plant behaviour in exclusively chemical–mechanical terms. Within this epistemological framework, the very idea of plant behaviour appeared problematic: plants grew but did not act; they reacted but did not decide. This approach has also profoundly influenced modern natural sciences. For a long time, behaviour was defined in relation to voluntary movement, the presence of a nervous system and the capacity for centralised cognitive processing. Plants, lacking a brain and incapable of locomotion, thus appeared to be excluded from the domain of ethology.

However, as early as the 19th century, some observations began to challenge this traditional view. Charles Darwin, in his book The Power of Movement in Plants, published in 1880, observed that the root tips appeared to perform a coordinating function analogous, at least in a functional sense, to that of a nerve centre in lower animals. Although this insight did not gain immediate acceptance, it anticipated a theme destined to re-emerge forcefully in contemporary debate. In recent decades, advances in plant physiology, molecular biology, behavioural ecology and comparative neuroscience have profoundly altered the theoretical framework. Plants are now recognised as organisms capable of perceiving complex environmental signals, integrating information from different sources and modulating their responses according to the context. Such capabilities do not necessarily imply consciousness or intentionality in the human sense, but they do highlight the inadequacy of a purely mechanistic conception of the plant world. Rather, the plant emerges as a dynamic system, capable of developing sophisticated adaptive strategies through regulatory processes spread throughout the entire organism. These phenomena have given rise to a lively interdisciplinary debate. Some authors speak of “plant neurobiology”, whilst others prefer more cautious terms such as “adaptive plasticity” or “distributed behaviour”. The empirical investigation of plant cognition primarily falls within the remit of cognitive science. However, extending concepts such as cognition, intelligence and behaviour to organisms lacking nervous systems raises important conceptual questions in the philosophy of biology. This is particularly the case when it comes to the scope and meaning of these categories.

To what extent is it legitimate to use cognitive categories to describe the plant world? Does intelligence necessarily require a brain? Do non-neural forms of cognition exist? The issue is not merely one of terminology, but touches on deeper questions concerning the very definition of behaviour, learning and adaptation. In this sense, the study of plants now constitutes one of the most fascinating fields for interdisciplinary reflection on the foundations of contemporary biology. This review addresses these issues from an evolutionary and philosophical perspective. After examining the concept of plant behaviour, it will analyse the adaptive dynamics of plants, the mechanisms of intra- and interspecific communication, and the debate on plant intelligence. Finally, it will discuss the epistemological and ontological implications of this research for contemporary philosophy. I argue that contemporary plant biology does not support the attribution of intelligence to plants in the strong mentalistic sense, involving conscious, representational or deliberative problem-solving capacities, as are commonly attributed to animals with nervous systems. Instead, it shows that plant behaviour is best understood as a form of distributed adaptive regulation shaped by evolution. I argue that the main philosophical contribution of plant research is not to show that plants possess minds comparable to those of animals, but rather to necessitate a conceptual revision of categories such as behaviour, cognition, and agency. Throughout this review, I adopt the following operational strategy: first, I describe the observable biological phenomenon; then, I identify its underlying mechanism; only afterwards do I discuss whether cognitive terminology is conceptually justified.

This review defends a non-representational and broadly enactive position, which is constrained by evolutionary and operational criteria. It is not assumed that every instance of adaptive self-maintenance is cognitive. Cognition is only attributed where there is context-sensitive integration of multiple signals, flexible selection among alternative responses, retention or use of information beyond the immediate stimulus, and organism-level adjustment that cannot be adequately characterised by a simple stimulus–response description. These criteria are intended as operational thresholds rather than as evidence of consciousness or mental representation. They therefore only support a minimal, non-conscious conception of plant cognition.

Before addressing the topic of plant behaviour, it is necessary to clarify what is generally meant by “behaviour” in a biological context. Traditionally, the concept has been developed primarily in relation to animals and their interactions with the environment. From the classical perspective of ethology, behaviour was generally defined as the set of observable actions through which an organism responds to external stimuli [1,2,3]. However, such a definition tends to favour organisms possessing mobility and a nervous system, thereby implicitly excluding the plant kingdom. For this reason, numerous contemporary scholars have proposed a redefinition of the concept in broader and more functional terms.

As I have already mentioned in the introduction, Darwin’s theory of evolution provides the fundamental conceptual framework for understanding plant behaviour [4]. In On the Origin of Species, Darwin already attached great importance to plant movements and the sensitivity of roots, which he regarded as structures capable of orienting the organism in space. In the book The Power of Movement in Plants (1880), written with Francis Darwin, the English naturalist observed that the root apex behaves “like the brain of a lower animal”, coordinating the responses of the entire plant [5] (p. 543). Darwin’s insight anticipated a perspective that is central today: behaviour does not necessarily coincide with locomotion. In evolutionary biology, behaviour can be defined as an organised sequence of plastic responses to environmental stimuli, geared towards survival and reproduction. From this perspective, plants too possess behavioural repertoires. Plant adaptation manifests itself through extremely sophisticated morphological, physiological and chemical strategies. Plants regulate root growth according to nutrient availability; they orient their leaves and stems in response to light gradients; they activate chemical defences against herbivores and pathogens; and they adjust their reproductive timing in response to climatic conditions. From an evolutionary perspective, these capabilities do not imply conscious intent. Rather, they represent the result of selective processes that have favoured biological systems capable of responding flexibly to environmental pressures. However, the degree of integration and plasticity of these responses raises theoretical questions about the nature of behaviour itself.

In a functionalist framework, behaviour can be understood as any organised response through which an organism modifies its internal state or its relationship with the environment in order to increase its chances of survival and reproduction. Such a definition also allows for the inclusion of plants, whose behaviour is not manifested through locomotion but through processes of growth, physiological regulation and structural modification.

Today it is reasonable to speak of plant behaviour if the term is used in an operational sense: a measurable change in state, growth, movement, chemical release or physiological priority that depends on environmental information and alters the plant’s subsequent interaction with its environment [6]. Plant behaviour is expressed primarily through developmental plasticity. A plant is not a static organism that rigidly follows a predetermined genetic programme; on the contrary, it continually modifies its form in response to environmental conditions. Light, gravity, water availability, soil chemistry, temperature and the presence of competing organisms profoundly influence plant structure and metabolism. Phenomena such as phototropism and gravitropism clearly demonstrate this dynamic. A plant directs its growth towards the light not through immediate movement, but through the differential redistribution of auxins, hormones that regulate cell elongation [7,8]. Similarly, roots modify their development in response to the distribution of water and nutrients in the soil. These responses cannot be regarded as mere mechanical automatisms. They involve the ability to integrate multiple signals and to modulate the response in a context-dependent manner. A single species can develop profoundly different morphological configurations depending on the environment in which it grows.

The concept of phenotypic plasticity takes on decisive importance here. Plants do not follow rigid genetic programmes; they modulate their development in response to ecological conditions. Genetically similar individuals can take on radically different forms depending on the environment. According to Mary Jane West-Eberhard, plasticity represents one of the main adaptive resources of living organisms, as it enables them to produce different phenotypes in response to variable conditions [9]. In the case of plants, this ability is particularly well-developed, precisely because of their immobility. Plants cannot escape from a hostile environment; they must therefore modify themselves. It is precisely this condition that makes plant behaviour so interesting from an evolutionary perspective. At the heart of plant behaviour lies a complex capacity for perception of the environment. Plants are equipped with sophisticated sensory systems that enable them to detect extremely subtle variations in external conditions. They perceive the quality and intensity of light through specialised photoreceptors such as phytochromes and cryptochromes; they detect gravity via intracellular structures called statoliths; they respond to mechanical stimuli such as touch and wind; they recognise chemicals produced by other organisms and even variations in the concentration of nutrients present in the soil. Plants’ perceptual capacity is therefore far more sophisticated than traditionally imagined. These are not merely local reactions, but systems for the continuous monitoring of the environment. Once a stimulus is perceived, the plant must integrate it and transform it into a coherent response. This process takes place through complex biochemical networks involving plant hormones, ionic flows and electrical signals. Auxins, for example, play a fundamental role in regulating growth.

In the presence of lateral light, they accumulate on the shaded side of the stem, stimulating differential growth that directs the plant towards the light source [10,11]. Of particular interest is the discovery of electrical signals in plants. Recent studies have shown that plants are capable of generating electrical impulses that propagate through vascular tissues relatively rapidly [2,12]. These signals are not identical to the action potentials found in animal neurons, but they share significant functional similarities. They enable coordination between different parts of the plant, contributing to the regulation of physiological responses. When a leaf is damaged by a herbivore, for example, electrical signals can propagate rapidly throughout the entire organism, triggering defence mechanisms even in regions not directly affected.

All these phenomena suggest that information processing in plants occurs through a decentralised logic. There is no central brain coordinating behaviour; on the contrary, the entire organism participates in regulatory processes. This decentralised organisation constitutes one of the most innovative aspects of contemporary plant biology. It challenges the idea that behavioural complexity necessarily requires the presence of a centralised nervous system. In this sense, plant plasticity has led some philosophers of biology to speak of distributed agency. The plant organism does not possess a single decision-making centre, but coordinates multiple processes through widespread networks of hormonal, electrical and chemical signalling. It appears as a decentralised system of information processing. From this perspective, the notion of plant agency must not be confused with human psychological intentionality. Rather, it refers to an organism’s capacity to maintain its own organisation through selective interactions with the environment. Plants are not conscious beings in the traditional sense, nor are they mere passive automata. This perspective ties in with contemporary theoretical models such as enactivism and complex systems theory, according to which cognition emerges from the dynamic interaction between organism and environment [13]. Life itself can be interpreted as a continuous process of producing biological meaning.

With regard to interactions with the environment, one of the most innovative fields of plant research concerns chemical communication. Plants do not live in isolation but are embedded in extremely complex ecological networks. Their survival depends on their ability to interact with other organisms, including fungi, bacteria, insects and other plants. Numerous studies have demonstrated that plants release volatile organic compounds in response to mechanical damage or herbivore attack. These signals can then modify the defensive responses of neighbouring plants [14,15,16]. These substances can trigger preventive defences in neighbouring individuals. When a plant is attacked by herbivorous insects, for example, it may emit chemical signals that induce other plants of the same species to produce toxic or deterrent metabolites. In some cases, the volatile compounds attract natural predators of the herbivores, forming a complex form of triadic interaction [14]. These phenomena have often given rise to anthropomorphic interpretations: terms such as alarm, cooperation or plant language are used. However, from an epistemological point of view, a distinction must be made between heuristic metaphor and literal description. Plants do not possess symbolic language in the human sense, but they participate in highly organised biological signalling systems. Beyond the empirical characterisation of signalling processes, an additional conceptual issue is whether these processes can properly be described as “communication”. This distinction has been the subject of extensive discussion within the philosophy of biology and biosemiotics, where the relationship between signalling, information, and intentional communication remains controversial [15,17].

If communication is understood as the transmission of information that alters the behaviour of other organisms, then plants do indeed communicate. If, on the other hand, it requires conscious intentionality or symbolic representations, the term becomes problematic.

Plant communication should not be interpreted in anthropomorphic terms, as if plants spoke in the human sense of the word. However, it is clear that they use chemical signals to influence the behaviour of other organisms and coordinate their own responses. The subsoil, too, is a space of extraordinary biological complexity. Mycorrhizal associations between roots and fungi form underground networks through which nutrients and signals are transferred [18]. Through these connections, plants can share carbon, nitrogen and information relating to environmental stress. Some studies even suggest that larger individuals may support younger plants through the transfer of nutrients. Some authors have described these networks as a sort of “wood wide web”, emphasising their cooperative nature [19,20]. Larger trees appear to support younger individuals through the transfer of resources; stress signals can propagate through the shared root system. Although such interpretations are sometimes overly speculative, they highlight an important theoretical point: plants cannot be understood as isolated individuals. The plant organism is intrinsically relational. This conception challenges the individualistic paradigm of classical biology and aligns with ecological and systemic models in which life emerges from networks of interdependence. Biological identity appears to be distributed between the organism and its environment. Thus, the so-called “wood wide web” serves as an effective metaphor for describing ecosystems characterised by profound interdependence. Plant behaviour cannot be understood exclusively at the individual level; rather, it emerges from the continuous interaction between different organisms within complex ecological networks.

The evolutionary interpretation of plant behaviour constitutes one of the main theoretical models in contemporary biology, clearly highlighting the complex nature of plant individuals within complex ecological networks, as discussed in the previous paragraph. The theory of natural selection allows us to understand how plants’ adaptive strategies have emerged through gradual processes of functional optimisation, shaped over millions of years by environmental pressures. In the classical formulation of Darwinism, adaptation is interpreted as the result of the action of natural selection on random heritable variations. Organisms possessing advantageous characteristics in a given environment tend to produce a greater number of offspring, leading in the long term to the spread of these traits throughout the population. Plants constitute one of the most extraordinary examples of the explanatory power of this model. The remarkable diversification of angiosperms, the emergence of highly specialised reproductive strategies, and co-evolution with pollinating insects serve as paradigmatic examples of evolutionary adaptation. This phenomenon cannot be viewed as merely a passive reaction to the environment, which is considered an external and immutable reality to which organisms must simply adapt [21,22]. Plants display a unique ability to actively modify the ecological conditions in which they live. Through shading, the production of chemicals, the modification of soil structure and interaction with microbial communities, they contribute to the construction of their own ecological niches [23].

For a long time, evolution was interpreted primarily in relation to animals. Mobility, predatory behaviour, sexual competition and the presence of complex nervous systems seemed to represent the prime arena of evolutionary adaptation. Plants, on the other hand, were regarded as relatively simple organisms, whose evolution appeared to be linked above all to passive morphological changes. However, starting with Darwin’s theory of evolution and continuing with contemporary research, it has been shown not only that this distinction is profoundly reductive, but also that the plant world itself is an example of complex and active evolutionary adaptation, as plants face extremely complex ecological problems and develop sophisticated adaptive strategies to resolve them. Their apparent immobility does not constitute an evolutionary limitation, but rather the starting point for the emergence of alternative modes of adaptation. The condition of sessility—that is, the inability to move through space to escape environmental changes—has exerted a decisive selective pressure in the evolutionary history of plants. Unable to migrate rapidly to favourable environments, they have had to develop strategies based on structural flexibility, physiological plasticity and the ability to modify their own development in response to their environment, as well as to modify the environment itself.

The niche construction theory, developed by Richard Lewontin and subsequently by F. John Odling-Smee, Kevin Laland and Marcus Feldman, has emphasised that organisms are not merely the objects of reactive adaptation, but also agents that transform the selective environment [24,25]. The relationship between organism and environment takes on a circular nature: the environment influences the evolution of organisms, but organisms in turn modify the environment, altering future selective pressures. Once again, plants constitute a particularly significant example of this dynamic. Entire ecosystems—forests, grasslands and wetlands—can be interpreted as the products of the cumulative activity of successive generations of plant organisms. In this sense, the importance of phenotypic plasticity comes to the fore once again, as it represents one of the most significant evolutionary innovations in the plant kingdom. In the case of plants, plasticity is particularly evident in the regulation of growth. A single species can take on profoundly different forms depending on the availability of light, water and nutrients. In shaded environments, for example, many plants develop broader, thinner leaves to increase light absorption; in arid environments, by contrast, they tend to reduce leaf area and invest more in root development. These modifications are not merely mechanical reactions, but adaptive strategies selected over the course of evolution. Plants continuously adjust their energy balance, allocating resources between growth, reproduction and defence in response to environmental conditions. One of the most fascinating aspects of plant evolution concerns precisely this allocation of resources. Every organism has a limited amount of energy, which must be distributed amongst various biological functions.

Investing in growth means diverting resources away from defence; investing in reproduction can reduce the ability to withstand environmental stresses. Such evolutionary trade-offs constitute one of the fundamental principles of the theory of evolutionary adaptation. Plants’ behavioural strategies continually reflect this dynamic balance, which underlies evolution. In environments characterised by intense competition for light, many species develop accelerated vertical growth. This phenomenon, known as shade avoidance syndrome [26,27], is regulated by the perception of variations in the light spectrum caused by the presence of other plants. Through phytochromes, plants detect a decrease in red light and activate responses that promote stem elongation. This strategy increases access to light but also entails considerable costs. Excessively rapid growth can, in fact, reduce structural stability and increase vulnerability to water stress. The adaptive response therefore arises from an evolutionary balance between advantages and disadvantages. Defence systems also clearly demonstrate the role of natural selection in the evolution of plant behaviour. Plants have developed an extraordinary variety of chemical and structural strategies to counter herbivores and pathogens. Many species produce alkaloids, tannins, terpenes and other toxic or repellent substances. Others develop thorns, lignified tissues or particularly robust defensive structures. The production of defences entails a high energy cost. Consequently, plants must modulate their defensive investment in relation to the probability of attack. Numerous studies have shown that the synthesis of defensive substances increases significantly following an attack by herbivores [16,28].

This suggests that plants do not keep all defence mechanisms constantly active but dynamically regulate their response according to environmental risk. This aspect reveals a fundamental element of evolutionary adaptation: the ability to optimise the use of resources and thus actively respond to external circumstances.

The evolution of symbiotic relationships also provides a further example of the adaptive complexity of the plant world. Mycorrhizal associations between roots and fungi—already mentioned in the previous paragraph—constitute one of the most important evolutionary events in the history of terrestrial plants. Through these symbiotic relationships, plants increase their ability to absorb nutrients and water, whilst the fungi receive carbohydrates produced through photosynthesis. This cooperation enabled the earliest plants to colonise terrestrial environments that were relatively nutrient-poor. From an evolutionary point of view, mycorrhizal networks demonstrate that natural selection does not exclusively favour competition but can also promote forms of ecological cooperation. Another key theme concerns the adaptation of plants to climate change [29,30]. Throughout their evolutionary history, plant organisms have faced profound environmental changes, developing extremely sophisticated resilience strategies. The emergence of drought-tolerance mechanisms, the regulation of stomatal opening, seed dormancy and the ability to synchronise flowering with seasonal variations are all examples of adaptations selected in response to environmental pressures.

Within the complex dynamics described so far—which also, and above all, characterise plant evolution—lies the concept of co-evolution. Many characteristics of plants can only be understood in the light of evolutionary processes involving several species simultaneously. The relationship between flowering plants and pollinators is one of the best-known examples. The shapes, colours and scents of flowers are often the result of a long history of mutual adaptation between organisms belonging to different evolutionary lineages [31].

Darwin himself had recognised the importance of such phenomena. In his study of orchids, he demonstrated how the structure of certain flowers was inseparable from the morphology of pollinating insects [32]. Evolution therefore does not proceed through isolated organisms, but through networks of ecological relationships that mutually influence one another over time. Once again, recent research on mycorrhizal symbiosis has further reinforced this relational view of evolution. The colonisation of the land by the first plants, some 470 million years ago, is thought to have been made possible by their collaboration with fungi capable of facilitating the absorption of nutrients. The evolutionary identity of plants appears inseparable from the relationships they maintain with other organisms.

Therefore, if evolution is a fundamentally relational process, then biological individuality must also be rethought. Plants demonstrate particularly clearly that an organism is not a self-sufficient entity, but a node within a network of ecological and historical interactions. Adaptation does not concern the survival of isolated individuals solely, but rather the continuous transformation of systems of relationships involving organisms, populations and ecosystems. Whilst not calling into question the central role of natural selection, the importance of the interaction between development, environment and plasticity has been highlighted. Plants therefore constitute a prime model for understanding the dynamic nature of evolution. Indeed, they show that adaptation does not simply consist in the survival of the fittest, but in the emergence of flexible strategies capable of responding to ecological complexity. Evolutionary theory also helps to overcome the traditional dichotomy between active animals and passive plants. Both groups develop strategies aimed at optimising fitness, albeit through profoundly different mechanisms. In the case of plants, behaviour emerges from networked, modular processes that are deeply integrated with the environment. It is precisely this specificity that makes the plant world one of the most fascinating fields in contemporary biology.

The notion of plant behaviour is useful only if it is defined operationally in terms of observable and measurable responses, without presupposing subjective mental states or psychological capacities. Plant behaviours include directional responses, temporal modulations, prioritisation of conflicting signals, changes in the growth space, signal emissions and physiological reorganisation that depend on the context and develop over time. In this sense, behaviour does not equate to visible movement or a mental state; rather, it encompasses processes in which the plant perceives, integrates, selects a response and modifies its ecological trajectory [33].

One of the most innovative and controversial aspects of contemporary research into plant behaviour concerns the possibility that plants exhibit forms of memory and learning. For a long time, such capacities were considered the exclusive preserve of organisms possessing a central nervous system. Memory was interpreted as the result of complex neuronal processes, whilst learning was associated with behavioural modification through experience. Plants, lacking neurons and incapable of voluntary movement, therefore seemed to be excluded from this biological realm. However, numerous recent studies have progressively challenged this view, demonstrating that plant organisms possess sophisticated abilities to record environmental experiences and modulate future responses [34,35,36]. Of course, speaking of plant memory does not mean attributing forms of consciousness analogous to those of humans to plants. The issue is rather to understand whether memory should be defined exclusively in relation to nervous systems, or whether it can be interpreted more broadly as a biological capacity to retain information relating to previous experiences. From this perspective, plants appear to exhibit numerous phenomena attributable to forms of physiological memory.

One of the best-known examples is provided by experiments on Mimosa pudica. Normally, this plant reacts to mechanical stimuli by rapidly closing its leaves, a behaviour that reduces the risk of damage from herbivores. Studies conducted by Monica Gagliano and her colleagues have shown that, when repeatedly subjected to harmless stimuli, the Mimosa tends to progressively diminish its defensive response: it reduces the closure of its leaves and maintains this response for prolonged periods. This phenomenon has been interpreted as a form of habituation and physiological memory [34]. The epistemological question is whether such processes can be defined as genuine learning or not. In the most basic sense, learning means permanently altering behaviour on the basis of experience. From this point of view, certain plant phenomena would meet this criterion. If the phenomenon of habituation is traditionally regarded as one of the simplest forms of animal learning, then its presence in plants suggests that even organisms without a brain can modify their behaviour on the basis of experience. Of particular interest is the fact that the modified response persists over time. This implies that the plant is not merely reacting to the present stimulus but retains a physiological trace of the previous experience. This ability to retain information is one of the key factors fuelling the contemporary debate on plant cognition. From a biological perspective, plant memory appears to be based on processes that are profoundly different from neuronal ones. Plants utilise biochemical networks, epigenetic modifications, changes in hormone concentrations and alterations in gene expression to record the effects of environmental experiences.

One of the most widely studied phenomena is so-called defensive priming [37,38]. As mentioned earlier, when a plant is attacked by pathogens or herbivores, certain defence systems are activated and subsequently remain in a state of heightened sensitivity. If the organism is exposed to a similar stressor again, the response will be faster and more effective. This mechanism represents an extremely advantageous adaptive strategy from an evolutionary perspective. Constantly activating all available defences would, in fact, require an enormous expenditure of energy. Through priming, however, the plant can optimise the use of resources whilst maintaining a state of selective readiness. Plant adaptation thus emerges not only as an immediate response to current stimuli, but as the ability to utilise information derived from past experience [16,39]. The ecological memory of plants is also particularly significant in relation to climate change and environmental variability, as I have already seen in relation to evolutionary adaptation. Plants are organisms that are highly exposed to seasonal fluctuations and changes in their ecological context. The ability to record information relating to past events allows them to synchronise their development more effectively. A significant example concerns vernalisation, a process through which certain plants acquire the ability to flower only after being exposed to low temperatures for a specific period. In this case, the organism retains a sort of physiological memory of winter, which enables it to regulate flowering at the most favourable time from a reproductive perspective. Seeds display sophisticated adaptive capabilities linked to environmental memory. Many species are able to remain dormant until specific conditions of temperature, humidity or light indicate the presence of an environment favourable to germination.

All these mechanisms demonstrate how plant behaviour is closely intertwined with temporal processes. Plants do not simply react passively to their current environment but continuously integrate information relating to the past and future probabilities. The role of epigenetics is also particularly significant. Recent studies have shown that certain environmental experiences can produce stable changes in gene expression without directly altering the DNA sequence [40,41]. These epigenetic modifications can, in some cases, be passed on to subsequent generations, influencing the adaptive response of the offspring. This implies that individual experience can indirectly contribute to evolutionary processes. As I have already mentioned in the previous paragraph, although these phenomena do not call into question the fundamental principles of natural selection, they do suggest a more dynamic and complex view of biological adaptation. Plants demonstrate that evolution does not depend solely on random mutations selected over the long term, but also on the ability of organisms to modulate their own development in response to the environment. This perspective has profound theoretical implications. Traditionally, the distinction between physiology and behaviour was relatively clear-cut: behaviour was associated with coordinated and purposeful actions, whilst physiology concerned automatic internal processes. In the case of plants, however, this distinction is gradually becoming blurred. Growth, development, metabolic regulation and ecological adaptation constitute deeply integrated aspects of a single dynamic system. Plant learning, although radically different from that of animals, thus shows that the ability to utilise experience does not necessarily require neurons and synapses. This does not mean that plants think or are conscious in the human sense of the term.

They demonstrate that biological memory can take on far more diverse forms than traditionally imagined.