Plants That Can Survive Without Water

Several hundred plant species can lose virtually all the water in their leaves and stems, shut down every measurable sign of life, and then spring back to full function within hours of getting wet again. Scientists call these “resurrection plants,” and their ability goes far beyond the drought-dodging strategies of cacti or succulents. Where a cactus hoards water to avoid drying out, a resurrection plant lets itself dry completely and survives anyway. Understanding how they pull this off has become one of the more promising threads in agricultural research, and the biology behind it is stranger than most people expect.

What “Surviving Without Water” Really Means

There is an important distinction between plants that tolerate desiccation and plants that simply avoid or resist drought. A cactus stores water in thick, fleshy tissue and rations it during dry spells. An oak tree sends deep taproots toward the water table. Both strategies keep the plant’s cells hydrated. Resurrection plants take the opposite approach: they let their cells dehydrate so completely that all measurable cellular activity stops. They become, for all practical purposes, dead-looking brown husks. Yet when water returns, they resume healthy cellular function within minutes to hours.

Researchers define true desiccation tolerance as surviving a state where the tissue’s water potential drops below an extremely negative threshold, a level at which essentially no free water remains for biological processes. At that point, ordinary plant tissue would suffer irreversible damage to membranes, proteins, and DNA. Resurrection plants avoid this destruction through a suite of protective mechanisms, some built in permanently and others switched on as drying begins.

The Sugar Glass and Molecular Shields

One of the most remarkable defenses involves turning a plant’s insides into something like glass. As a resurrection plant dries, it accumulates large quantities of sugars, especially sucrose and a related sugar called raffinose. These sugars form a rigid, glassy matrix through extensive hydrogen bonding, a process known as vitrification. In the resurrection plant Haberlea rhodopensis, sucrose and raffinose levels peak during the final stage of drying. This glassy state drastically slows molecular movement inside cells, preventing proteins from unfolding and membranes from fusing together. The plant’s internal structures are essentially frozen in place, preserved in a stable arrangement until water shows up again.¹

Working alongside the sugars is a family of proteins called late embryogenesis abundant proteins, or LEAs. These molecules are unusual: they lack the rigid three-dimensional shapes that most proteins depend on. Instead, they stay loose and disordered in solution, which gives them a proportionally large surface area. As water vanishes from a cell, LEAs bind to other proteins and cellular structures that have lost their surrounding water layer, essentially standing in for the missing hydration shell. By clinging to vulnerable molecules, they prevent the kind of destructive clumping and crowding that kills ordinary plant cells during extreme drying.²

Coming Back From the Brink

Drying out is only half the challenge. Rehydration is arguably more dangerous, because water flooding back into damaged tissue generates a burst of reactive oxygen species, the same corrosive molecules that antioxidant supplements claim to fight. In a normal plant, this oxidative shock would shred membranes and DNA. Resurrection plants counter it with a strong antioxidant defense system that remains active even while the plant is bone-dry and ramps up further within the first few hours of rehydration.³

In Haberlea rhodopensis, enzymes involved in the ascorbate-glutathione cycle play a central role in neutralizing these dangerous molecules during drying, and they stay primed for rehydration.⁴ At the onset of recovery, antioxidant enzyme activity either stays at the elevated levels seen in the dried state or increases further, buying the plant time to rebuild its normal metabolism before oxidative damage accumulates. The whole system suggests careful preparation: resurrection plants do not simply survive drying and hope for the best. They pre-position molecular defenses so that recovery can begin immediately.

Walls That Fold Without Breaking

Plant cells are wrapped in a rigid cell wall, which in most species would crack or tear if the cell shrank dramatically. Resurrection plants get around this by remodeling their walls as drying proceeds. In Craterostigma wilmsii, for example, leaves undergo extensive shrinkage during drying accompanied by considerable cell wall folding. Research on this species found that dehydration triggers significant changes in the types and amounts of cell wall sugars, including increases in xyloglucan and certain pectins, which alter the mechanical properties of the wall so it can crumple inward like a deflating balloon without sustaining permanent damage.⁵ When water returns, the wall unfolds, and the cell plumps back to its original shape.

The visual effect can be dramatic. Selaginella lepidophylla, sometimes sold as the “rose of Jericho,” curls its stems into a tight brown ball during drying. The outer stems lose roughly half their weight within an hour, while the inner stems dry more slowly, taking about five hours. This differential drying rate drives the curling motion, with the outer stems contracting faster than the inner ones.⁶ Add water and the ball opens back up, which is the parlor trick that makes it a popular novelty gift, but the underlying biology is a genuine survival strategy. Curling inward shields the inner, younger tissue from sun and wind exposure during the dry period.

Two Ways to Handle Sunlight in a Dry Body

Photosynthesis creates a specific vulnerability during drying. The light-harvesting machinery in chloroplasts continues absorbing solar energy even when there is too little water to run the normal chemical reactions. That excess energy produces destructive reactive oxygen species. Resurrection plants have evolved two fundamentally different solutions to this problem.

Some species, called homoiochlorophyllous types, keep their chlorophyll and thylakoid membranes largely intact through the dry period. Plants like Haberlea rhodopensis, Craterostigma species, and Myrothamnus flabellifolius take this approach, deactivating and reactivating components of the photosynthetic machinery in a specific sequence during drying and rehydration. They rely on physical tricks to reduce light exposure while dry: curling their leaves, accumulating pigments like anthocyanins that act as sunscreen, or growing reflective hairs.⁷

Other species, the poikilochlorophyllous types, take a more radical route: they dismantle their photosynthetic machinery entirely during drying. Plants like Xerophyta humilis and Xerophyta viscosa gradually degrade their chlorophyll as they dehydrate, producing nearly chlorophyll-free leaves by the time they are fully dry. The tradeoff is that recovery takes longer because they have to rebuild the entire photosynthetic apparatus from scratch upon rehydration.⁸ Each strategy has its niche. Keeping chlorophyll means faster recovery but higher risk of light damage while dry. Ditching chlorophyll is safer but slower.

Mosses and Soil Crusts

Resurrection plants are not limited to flowering species. Some of the most desiccation-tolerant organisms on land are mosses. Syntrichia ruralis, a dryland moss, has become a model organism for understanding how water-limited survival works at the genetic level. Genome sequencing has revealed differences in the copy number and activity of gene families associated with desiccation tolerance, offering clues about how different species have adapted to their specific habitats.⁹

The closely related moss Tortula ruralis uses a strategy biased toward repair rather than prevention. During drying, it does not recruit new messenger RNAs or shift dramatically which genes are being read. Instead, the main change happens at the level of protein production, adjusting which existing messages get translated into proteins. This repair-based approach means the moss can tolerate damage during drying and fix it upon rewetting, rather than needing to prevent all damage in the first place.¹⁰

At an even broader scale, biological soil crusts, the living skin that covers desert soils, are communities of mosses, cyanobacteria, lichens, and fungi that collectively tolerate extreme temperatures, drought, and intense solar radiation despite having relatively little time in a hydrated, metabolically active state.¹¹ These crusts stabilize soil, fix nitrogen, and cycle nutrients across vast stretches of arid land, making them ecologically far more important than their humble appearance suggests.

Desert Specialists That Push Water Use to the Limit

Not every plant that thrives without rainfall is a true resurrection species. Some have evolved extraordinary water-harvesting or water-stretching strategies instead.

Welwitschia mirabilis, the bizarre two-leaved plant that lives in the hyperarid Namib Desert and can persist for over a thousand years, employs multiple overlapping strategies. Studies of its root systems have found dense networks of fine roots extending upward from about 30 centimeters deep all the way to the ground surface, positioned to capture moisture from fog and dew. Isotopic analysis of leaf water suggests some passive uptake of fog water through stomata when they open at dawn.¹² This is not desiccation tolerance; the plant never fully dries out. But it survives in a place where conventional water sources are essentially absent.

Tillandsia ionantha, a small epiphytic bromeliad commonly called an air plant, absorbs water directly through its leaves rather than through roots. Its specialized leaf trichomes collect water by capillary action within a minute, and then aquaporin proteins shuttle that water into deeper leaf tissues over a period of about three hours.¹³ This two-phase system lets the plant grab moisture from humid air or brief rain without needing soil at all.

Succulents take yet another approach: storing large volumes of water in fleshy tissue and minimizing loss through low surface-to-volume ratios. The ribbed stems of many cacti serve a dual purpose. Ribs allow the stem to swell and shrink as water levels change, but they also increase the surface area compared to a perfectly smooth cylinder. The geometry involves a tradeoff: numerous low ribs provide moderate expandability with only a small increase in surface area, a design well suited to environments with short, frequent droughts.¹⁴

Where Desiccation Tolerance Came From

Almost every seed-bearing plant already packages desiccation tolerance into one structure: its seeds. Orthodox seeds dry to very low water contents before dispersal and can remain viable for years or decades. The prevailing hypothesis is that resurrection plants re-activated this seed-specific survival program in their leaves and stems. Evidence for this comes from the finding that genes normally expressed only in seeds, including LEA genes and antioxidant genes like 1-cys-peroxiredoxin, are turned on in the vegetative tissues of desiccation-tolerant plants.¹⁵

This re-activation appears to have happened independently at least eight times within flowering plants alone, suggesting that the genetic toolkit for surviving complete drying was always present but normally locked away for seed development. When environmental pressure was strong enough, certain lineages found ways to unlock that toolkit in leaves and roots too.¹⁶ In mosses and other non-vascular plants, desiccation tolerance in vegetative tissues is thought to be the ancestral condition rather than a re-invention, meaning the earliest land plants likely had it and most flowering plants lost it as they evolved other ways to manage water.¹⁷

A Resurrection Plant That Lives Underwater

One of the strangest members of the resurrection plant club is Chamaegigas intrepidus, an aquatic species that grows in ephemeral rock pools on granite outcrops in central Namibia. These pools fill during the rainy season and then bake dry in the sun. The plant survives the desiccated state between fillings, making it a resurrection plant that spends its active life submerged.¹⁸ Its existence undercuts the assumption that desiccation tolerance evolved only in dry habitats. Instead, unpredictable water availability, whether in a desert or in a temporary puddle on a rock, appears to be the real selective pressure.

Traditional Uses and Folk Medicine

Resurrection plants have a long history in traditional medicine across multiple cultures. In Arabian folk medicine, Anastatica hierochuntica (often called the “true” rose of Jericho) is soaked in water and the liquid drunk by women during childbirth, believed to ease delivery. In Malaysia, the same plant is popular among pregnant women because of its mineral content. Traditional practitioners have also used it as an analgesic, a liver protectant, and a treatment for epilepsy. Beyond childbirth, the plant’s leaves have been smoked to treat asthma, and infusions made from them have been used against coughs, kidney disorders, and gum disease.¹⁹

In the Americas, the resurrection fern Polypodium polypodioides was used by the Aztecs as a diuretic and treatment for kidney stones, and by the Houma people in cold infusions for treating sore mouths in infants and in decoctions for headache and bleeding gums. The breadth of these traditional applications has drawn attention from researchers screening resurrection plant metabolites for pharmaceutical activity, though rigorous clinical evidence for most of these uses remains thin.

Engineering Drought Tolerance Into Crops

The practical stakes of understanding resurrection plants are enormous. As climate change intensifies droughts in major agricultural regions, researchers are investigating whether the molecular tricks of resurrection plants can be transferred to crops. The goal is not necessarily to make wheat or rice survive complete desiccation, but to expand the range of water stress a crop can endure and keep growing under limiting conditions.²⁰

Since resurrection plants appear to have co-opted the seed desiccation program for use in leaves, and since crop plants already carry those same seed genes, the genetic raw material may already be in place.²¹ The challenge is figuring out how to switch those genes on at the right time, in the right tissues, without disrupting normal growth and yield. Work on CAM photosynthesis, the water-efficient carbon-fixation pathway used by cacti and succulents, is proceeding along similar lines: defining the core genetic modules needed for nocturnal carbon fixation and inverse stomatal regulation so that pieces of that system could be engineered into conventional crops.²² Neither approach has produced a commercially viable drought-proof crop yet, but the genetic evidence is further along than the cautious language of research papers tends to let on.

Dryland Shrubs as Climate Buffers

Even plants that are not desiccation-tolerant play a quiet but critical role in keeping arid ecosystems alive. Foundation species in drylands, typically deep-rooted shrubs, create microclimatic refuges for other organisms. Their canopies lower soil temperatures and raise soil moisture compared to bare ground, effects that persist even during extended megadroughts. Research has shown that these plants provide the most significant thermal refuge when growing alongside other vegetation, creating patches of relative comfort in otherwise brutal landscapes.²³ For the animals and smaller plants that shelter beneath them, the effective climate they experience is very different from what the landscape-level data would suggest. Lose the foundation shrubs, and the downstream collapse can be rapid, a dynamic that adds urgency to understanding how dryland plants of all types cope with water scarcity.