Unlike most plants, Balanophora contains no chlorophyll and cannot perform photosynthesis. It also lacks a conventional root system to draw water from the soil. Instead, it survives entirely by attaching itself to the roots of specific nearby trees and stealing the nutrients it needs. Some species and populations take this strangeness even further by producing seeds without fertilization — a reproductive strategy that is extremely rare among plants.

Scientists uncover the secrets of a long-mysterious plant

The genus Balanophora takes its name from its acorn-like appearance (Greek: balanos, acorn; phoros, bearing), and it has puzzled scientists for generations. Because the plant is rare and restricted to highly specific habitats that are increasingly threatened by human activity, most research has been limited to isolated populations.

That is now changing. A collaborative team from the Okinawa Institute of Science and Technology (OIST), Kobe University, and the University of Taipei has conducted a broad survey of Balanophora across its scattered and hard-to-reach habitats. Their findings, published in New Phytologist, trace the plant’s evolutionary history, reveal how its internal structures have adapted to a parasitic lifestyle, and open new doors for future research into this unusual lineage.

As study lead author Dr. Petra Svetlikova, Science and Technology Associate at OIST, explains: “Balanophora has lost much of what defines it as a plant, but retained enough to function as a parasite. It’s a fascinating example of how something so strange can evolve from an ancestor that looked like a normal plant with leaves and a normal root system.”

Shrinking plastids and life without photosynthesis

Parasitic plants often undergo dramatic internal changes as they become more dependent on their hosts. One common trend is the reduction or loss of plastids — a category of plant organelles that includes chloroplasts, which enable photosynthesis in most plants.

Even though Balanophora relies completely on its host trees for nutrition, the researchers found that it has not eliminated its plastids. Instead, these structures have been pared down to a minimal form. While non-parasitic plants may use up to 200 genes to build and maintain plastids, Balanophora retains only about 20. Despite this extreme reduction, more than 700 proteins are still transported into these plastids from the surrounding cell, indicating that they continue to perform essential functions.

Professor Filip Husnik, head of the Evolution, Cell Biology, and Symbiosis Unit at OIST, notes the surprise of this discovery. “That Balanophora plastids are still involved in the biosynthesis of many compounds unrelated to photosynthesis was surprising. It implies that the order and timing of plastid reduction in non-photosynthetic plants is similar to other eukaryotes, such as the malaria-causing parasite, Plasmodium, which originated from a photosynthetic ancestor.”

An ancient lineage shaped by islands

By examining samples from many different populations, the team reconstructed the evolutionary tree of Balanophora and traced how it spread across subtropical regions of East Asia. The plant belongs to the family Balanophoraceae, one of the oldest known groups of fully parasitic plants.

This family began diversifying during the mid-Cretaceous period, roughly 100 million years ago — making it one of the earliest land plant lineages to abandon photosynthesis entirely.

Reproduction without sex and the risks of survival

Balanophora‘s reproductive strategies are just as unusual as its appearance and lifestyle. Reproductive methods vary widely between species and even between populations. Some require fertilization to produce seeds, while others can also reproduce without fertilization, a process known as facultative agamospermy. In the most extreme cases, some species are obligately agamospermous, meaning they never reproduce sexually at all.

“Obligate agamospermy is exceedingly rare in the plant kingdom, because it typically carries a lot of negative downsides — lack of genetic diversity, accumulation of bad mutations, dependence on specific conditions, higher extinction risk, and so on,” says Dr. Svetlikova. “Fascinatingly, we found that the obligately agamospermous Balanophora species were all island species — and we speculate that more Balanophora species may be facultative, or even obligate, agamosperms.”

One advantage of this reproductive approach is that a single female plant can establish a new population after reaching an island. This ability allows Balanophora to spread quickly into the narrow ecological niche it prefers: dark, moist forest undergrowth where few other plants can survive.

A fragile future for a highly specialized plant

Despite its ability to clone itself, Balanophora is extremely selective about its hosts. Each population typically parasitizes only a small number of tree species. This specialization makes the plant especially vulnerable to environmental change.

Dr. Svetlikova emphasizes the importance of collaboration and conservation. “We’re very thankful to our collaborators Dr. Huei-Jiun Su and Dr. Kenji Suetsugu, experts on parasitic plants, for their help in sampling the studied Balanophora species, and to local authorities in Okinawa that allowed us to study these extraordinary plants,” she says. “Most known habitats of Balanophora are protected in Okinawa, but the populations face extinction by logging and unauthorized collection. We hope to learn as much as we can about this fantastic, ancient plant before it’s too late. It serves as a reminder of how evolution continues to surprise us.”

Earlier interpretations of data from NASA’s Cassini mission to Saturn led scientists to propose a deep ocean of liquid water hidden beneath Titan’s ice. When researchers tested that idea using computer models, however, the results did not align with the physical characteristics seen in the data. A closer reanalysis produced new — slushier — conclusions. These results may prompt scientists to revisit assumptions about other icy worlds and refine how they search for life on Titan.

“Instead of an open ocean like we have here on Earth, we’re probably looking at something more like Arctic sea ice or aquifers, which has implications for what type of life we might find, but also the availability of nutrients, energy and so on,” said Baptiste Journaux, a University of Washington assistant professor of Earth and space sciences.

The study, published Dec. 17 in Nature, was led by NASA, with contributions from Journaux and Ula Jones, a UW graduate student of Earth and space sciences in his lab.

Cassini’s Legacy and Titan’s Unusual Surface

The Cassini mission began in 1997 and continued for nearly two decades, gathering extensive information about Saturn and its 274 moons. Titan — shrouded by a hazy atmosphere — stands out as the only place besides Earth where liquid is known to exist on the surface. With temperatures near -297 degrees Fahrenheit, that liquid is methane, not water. Methane forms lakes on Titan and even falls from the sky as rain.

As Titan travels around Saturn in an elongated orbit, scientists noticed that the moon stretches and compresses depending on its position relative to the planet. In 2008, researchers argued that this pronounced flexing could only occur if a large ocean existed beneath Titan’s crust.

“The degree of deformation depends on Titan’s interior structure. A deep ocean would permit the crust to flex more under Saturn’s gravitational pull, but if Titan were entirely frozen, it wouldn’t deform as much,” Journaux said. “The deformation we detected during the initial analysis of the Cassini mission data could have been compatible with a global ocean, but now we know that isn’t the full story.”

A Subtle Time Lag Reveals a Slushy Interior

The new research adds an important factor that earlier studies did not fully consider: timing. Titan’s changes in shape lag roughly 15 hours behind the strongest pull from Saturn’s gravity. Moving a thick, sticky material requires more energy than shifting a free flowing liquid, similar to how stirring honey takes more effort than stirring water. By measuring this delay, scientists could estimate how much energy Titan absorbs as it deforms, offering insight into how thick or viscous its interior must be.

The amount of energy lost, or dissipated, inside Titan turned out to be far greater than expected if a global liquid ocean were present.

“Nobody was expecting very strong energy dissipation inside Titan. That was the smoking gun indicating that Titan’s interior is different from what was inferred from previous analyses,” said Flavio Petricca, a postdoctoral fellow at NASA’s Jet Propulsion Laboratory and lead author of the study.

Based on these findings, the researchers propose an interior made up largely of slush, with significantly less liquid water than previously assumed. This slushy material is thick enough to explain the delayed response to Saturn’s gravity, while still containing enough water to allow Titan to change shape.

Radio Signals and Extreme Physics Support the Model

Petricca reached these conclusions by analyzing the frequencies of radio waves transmitted from the Cassini spacecraft during close fly-bys of Titan. Journaux helped interpret the results using thermodynamics. His work focuses on how water and minerals behave under intense pressure, knowledge that is critical for understanding whether other planetary environments might support life.

“The watery layer on Titan is so thick, the pressure is so immense, that the physics of water changes. Water and ice behave in a different way than sea water here on Earth,” Journaux said.

At his planetary cryo-mineral physics laboratory at UW, researchers have spent years developing methods to recreate the extreme conditions found on other worlds. Using this work, Journaux provided Petricca and his colleagues with data describing how water and ice are expected to behave deep inside Titan.

“We could help them determine what gravitational signal they should expect to see based on the experiments made here at UW,” Journaux said. “It was very rewarding.”

What Slush Could Mean for Life on Titan

“The discovery of a slushy layer on Titan also has exciting implications for the search for life beyond our solar system,” Jones said. “It expands the range of environments we might consider habitable.”

While the idea of a vast ocean once fueled optimism about life on Titan, the researchers suggest the updated picture may actually improve the odds. Their analysis indicates that Titan’s freshwater pockets could reach temperatures as high as 68 degrees Fahrenheit. In these smaller volumes of water, nutrients would be more concentrated than in a large ocean, potentially making it easier for simple life forms to survive.

Although scientists do not expect to find fish swimming through Titan’s slushy channels, any life discovered there might resemble organisms found in Earth’s polar regions.

Journaux is also part of NASA’s upcoming Dragonfly mission to Titan, which is scheduled to launch in 2028. The findings from this study will help inform that mission, and Journaux hopes future data will provide both evidence of life and a definitive answer about the presence of an ocean beneath Titan’s ice.

Co-authors include Steven D. Vance, Marzia Parisi, Dustin Buccino, Gael Cascioli, Julie Castillo-Rogez, Mark Panning and Jonathan I. Lunine from NASA; Brynna G. Downey at Southwest Research Institute; Francis Nimmo and Gabriel Tobie from the University of Nantes; Andrea Magnanini from the University of Bologna; Amirhossein Bagheri from the California Institute of Technology and Antonio Genova from Sapienza University of Rome.

This research was funded by NASA, the Swiss National Science Foundation and the Italian Space Agency.

The researchers found a clear pattern at the state level. States that experienced the sharpest drops in church attendance between 1985 and 2000 also saw the largest increases in deaths from these causes during the same period.

A Trend That Began Before the Opioid Crisis

Deaths of despair are often associated with the arrival of OxyContin and other powerful opioids in the late 1990s. However, the new analysis indicates that the upward trend started earlier, at the same time religious participation began to decline.

“What we see in this study is the beginning of the story, before opioids became a major issue, and it shows rises in deaths of despair were already beginning to happen when the opioid crisis hit,” said Tamar Oostrom, co-author of the study and an assistant professor of economics at The Ohio State University.

Oostrom worked on the research with Tyler Giles of Wellsley College and Daniel Hungerman of the University of Notre Dame. The study was published online in the Journal of the European Economic Association.

Data Sources and Affected Populations

The research team combined survey data on religious involvement from the General Social Surveys with mortality records from the Centers for Disease Control and Prevention.

Their findings showed that the decline in religious participation was concentrated among white, middle-aged adults without a college degree. This was the same group that experienced the most pronounced increases in deaths of despair, Oostrom said.

The relationship between lower church attendance and higher mortality appeared consistently across genders and was seen in both rural and urban areas of the United States.

Blue Laws and Changes in Church Attendance

To strengthen their findings, the researchers examined the repeal of “blue laws,” which had previously restricted many businesses from operating on Sundays. These laws limited competition with church attendance by reducing alternative activities.

A major wave of repeals took place in 1985, when Minnesota, South Carolina, and Texas eliminated their blue laws. The researchers compared outcomes in those states with others that did not make similar changes at that time.

The analysis showed that repealing blue laws led to a 5- to 10-percentage-point drop in weekly attendance at religious services. In later years, those same states also experienced higher rates of deaths of despair.

Mortality Trends Before and After Opioids

Oostrom noted that deaths of despair among middle-aged white Americans had been steadily declining from the late 1970s through the early 1990s. That decline eventually stalled, a shift that aligns with both falling church attendance and the repeal of blue laws.

After OxyContin was introduced in 1996, mortality rates rose sharply.

“OxyContin and the opioid crisis made a bad situation worse, but the deaths of despair were already on the rise,” Oostrom said.

Why Churchgoing May Matter for Health

The study raises an important question: how could lower church attendance contribute to higher death rates?

Oostrom explained that people who stop attending religious services often lose social ties, which past research has shown play a crucial role in physical and mental health. However, the findings suggest that social connection alone does not fully explain the pattern.

The researchers did not observe similar declines in other types of social activities during the same period when church attendance was falling.

“Religion may provide some way of making sense of the world, some sense of identity in relation to others, that can’t easily be replaced by other forms of socialization,” Oostrom said.

She also emphasized that belief itself did not fade during the years studied.

“What changed is whether people identified as religious and whether they go to church. Those are the things that matter when it comes to deaths of despair,” she said.

Can Community Participation Reverse the Trend?

The findings raise the possibility that renewed involvement in religious organizations or even secular community groups might help counter rising mortality rates. However, the authors caution that existing evidence does not offer much optimism.

“To our knowledge, findings on this point have so far been pessimistic,” the researchers wrote.

Oostrom added that there is no clear sign that broader declines in community participation are reversing. She also noted that the positive effects of religious involvement on life satisfaction are difficult to reproduce through other forms of social engagement.

The growing role of social media in the 21st century may further reduce the likelihood of a meaningful reversal, she said.

“People are less religious now, and there hasn’t been a substitute that provides what religion provided to many people. And our paper suggests this could have long-term impacts on health and mortality,” Oostrom said.