This Fern Grows Rare‑Earth Crystals Inside Its Leaves – and It Could Rewrite ‘Green Mining’

• The discovery: A Chinese-led team reports that an evergreen fern, Blechnum orientale (also known as Blechnopsis orientalis), naturally accumulates rare earth elements (REEs) and within its tissues those REEs self‑assemble into nanoscale crystals of the mineral monazite (lanthanum‑dominant, “monazite‑(La)”). The peer‑reviewed study appeared online November 4, 2025, in Environmental Science & Technology. PubMed
• Where in the plant: The team observed REE nanoparticles precipitating in vascular bundles and epidermal tissues, then crystallizing into monazite under ambient conditions, forming dendritic nanocrystals through a plant‑mediated “self‑organization” (the authors also use the term “phytomineralization”). Xinhua News
• Why it matters: Monazite is a major industrial REE ore typically formed by geological processes — but natural monazite often carries uranium and thorium, complicating extraction and raising radioactivity concerns. The researchers and CAS summary say the biological monazite in the fern is “pure” and non‑radioactive, potentially easing processing hazards. (That attribute will need independent confirmation across sites.) Wikipedia
• Who’s behind it: Researchers at the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences (CAS), with collaborators including Virginia Tech geoscientist Michael F. Hochella Jr. (author list on PubMed). PubMed
• Bigger picture: REEs are critical for EV motors and wind‑turbine magnets, and supply chains are under environmental and geopolitical pressure (EU Critical Raw Materials Act; China’s tightened export controls and evolving licensing). The fern’s “green circular” approach — remediation plus recovery — could someday complement conventional mining. Reuters

What the scientists actually found

In Blechnum orientale, a known REE‑accumulating fern, rare‑earth ions taken up from soil first precipitate as nanoparticles between plant cells and then crystallize into monazite‑(La) inside leaf tissues. The EST authors describe dendritic nanocrystals forming under ambient temperatures via biologically induced mineralization coupled to a non‑equilibrium self‑organization process — a phenomenon they term phytomineralization. It’s the earliest report of REEs crystallizing as an intracorporal mineral phase in a hyperaccumulator plant. PubMed

A news summary from Xinhua — consistent with the paper — specifies that those self‑assembled phases occur in the vascular bundles and epidermis of the frond, where REE nanoparticles nucleate and grow into monazite‑(La). Xinhua News

CAS’s English‑language write‑up frames the process as a self‑protection mechanism: the fern “packages and seals” potentially harmful REE ions into a stable mineral lattice, effectively detoxifying them. english.cas.cn

Why this is a big deal for rare earths

Monazite is among the most important REE ores. In nature it often contains measurable thorium (and sometimes uranium) — a reason monazite processing can fall under radioactive materials rules. If biogenic monazite forming inside plants is indeed low in U/Th, that could (in principle) deliver a cleaner feedstock for separation. (Note: the paper’s abstract does not quantify U/Th; the “non‑radioactive” claim appears in CAS/Xinhua summaries and warrants replication.) Wikipedia

The strategic context makes the science feel urgent. REEs are essential for permanent magnets in EV motors and wind turbines, both expanding rapidly in clean‑energy transitions. At the same time, supply is concentrated and subject to licensing controls and policy risk, as seen in 2025 with China’s tightened export rules and parallel discussions of new licensing regimes; the EU’s Critical Raw Materials Act meanwhile sets targets to reduce single‑country dependence by 2030. European Commission

Plants really can make minerals — but this goes further

Biomineralization is well known in microbes and animals (think shells and bones), while the plant side has often been underestimated beyond familiar crystals like calcium oxalate and silica phytoliths. Reviews in the plant sciences emphasize that such minerals commonly form in specialized cells and can regulate ions or deter herbivores. The novelty here is REEmediated crystallization into a technologically relevant ore mineral inside a living plant. PubMed

How it could change “phytomining”

Phytomining (or agromining) uses plants that hyperaccumulate metals to farm elements from soil and then recover them from biomass. It has been piloted most successfully for nickel; for REEs, promising hyperaccumulators exist, but processing the bio‑ore and separating REEs have been the main bottlenecks. If plants can pre‑crystallize REEs into monazite‑type phases, that may simplify downstream steps. It doesn’t eliminate the need for careful chemistry, but it might start with a cleaner, pre‑concentrated solid. ScienceDirect

Notably, independent work has mapped scores of REE (hyper)accumulators via XRF screening of herbarium collections, and field studies show Dicranopteris linearis can reach g‑per‑kg REE levels and yield REE‑rich ash amenable to green fractionation — evidence that supply‑from‑plants is more than a curiosity. OUP Academic

The fern at the center: Blechnum orientale

The species — sometimes treated as Blechnopsis orientalis in taxonomy — is a widespread Asian fern known to local communities as an edible/medicinal plant. In the present study, its significance is geochemical: it acts like a “rare‑earth vacuum” in soils, then locks those elements into a phosphate mineral right in the leaf. Plants of the World Online

What experts are saying (and what they aren’t yet)

• The paper’s authors (Guangzhou Institute of Geochemistry/CAS with Virginia Tech) emphasize that “naturally formed nanoscale monazite” occurs in extracellular tissues under ambient conditions, and that the work “opens new possibilities for the direct recovery” of functional REE materials — language echoed in independent reporting. PubMed
• CAS’s news post states the biogenic monazite is “pure and non‑radioactive.” That’s promising, but it’s a claim from an institutional summary; broader isotopic/trace‑element datasets across sites and seasons will be essential to validate it. english.cas.cn
• Outside researchers have shown that REE hyperaccumulation is geographically and taxonomically wider than once believed, supporting the idea that plant‑based REE supply could be scaled if agronomy and processing hurdles are solved. OUP Academic

Caveats and open questions

1. Throughput & yield. Even strong hyperaccumulators concentrate REEs in the g/kg range of dry mass — impressive biologically, but small compared with ore tonnages. Scaling to industrial flows will require dedicated cropping systems, rapid biomass handling, and efficient separation. MDPI
2. Separation chemistry. REEs are chemically similar, so low‑impact separations remain the hard part. If biogenic monazite is really cleaner, it could reduce radioactive waste, but solvent extraction or novel alternatives will still be needed. ScienceDirect
3. Ecology & ethics. Moving hyperaccumulator species outside their native ranges or planting them on marginal lands requires biosecurity and land‑use safeguards; any “green mining” must truly be restorative, not just relocated extraction. (CAS explicitly envisions remediation of REE tailings alongside recovery.) english.cas.cn
4. Policy headwinds. As export controls and licensing regimes shift, plant‑based supply won’t be insulated from geopolitics; it could complement (not replace) mines, recycling, and processing hubs the EU and U.S. are trying to build. Reuters

How it fits the 2025 REE landscape

• Demand drivers: EVs and wind are the biggest magnet markets; the IEA calls REEs “essential” for permanent magnets in these systems. IEA
• Supply concentration: China remains the dominant force in mining, separation, and magnets; the EU’s CRM Act sets 2030 targets to limit dependence on any single country, and recent policy steps show tightened Chinese controls with potential new licensing. European Commission
• Industry signals: Outside China, companies like Lynas are expanding despite profitability swings and plant‑ramp uncertainties, underscoring the need for diverse and cleaner supply options — where phytomining might eventually play a role. Reuters

What to watch next

• Independent replication in other Blechnum populations and soils; chemical profiling (including U/Th) of the biogenic monazite. PubMed
• Process engineering trials that isolate plant‑formed monazite from biomass with low reagents/low waste. (Lab‑scale “green fractionation” on REE bio‑ores already exists.) ScienceDirect
• Agro‑ecological models that pair tailings restoration with REE recovery, verifying real‑world mass balance and economics. english.cas.cn

Sources & further reading

• Peer‑reviewed study: He, L. et al. “Discovery and Implications of a Nanoscale Rare Earth Mineral in a Hyperaccumulator Plant,” Environmental Science & Technology (online Nov 4, 2025). (Abstract, authors, affiliations.) PubMed
• Study details in news releases: Xinhua; Chinese Academy of Sciences (Newsroom summary with additional claims about non‑radioactivity and green circular model). Xinhua News
• Independent news coverage: South China Morning Post report summarizing the team’s claims and “direct recovery” framing. South China Morning Post
• Plant biomineralization background: He & colleagues (2014) review; Ensikat et al. (2021) on biominerals in plants. PubMed
• REE hyperaccumulators & bio‑ore processing: Annals of Botany (2024) herbarium screening; Minerals (2024) on Dicranopteris bio‑ore and REE recovery; EST (2023) transporter NREET1 in D. linearis. OUP Academic
• Monazite and radioactivity context: USGS and reference summaries on U/Th in monazite and radioactivity in extraction. Wikipedia
• Rare‑earths in clean energy & policy: IEA on critical minerals; EU Critical Raw Materials Act; recent reporting on China’s export controls and licensing. Reuters

Bottom line

A fern that grows rare‑earth crystals inside its leaves is more than a headline — it’s a proof‑of‑principle that biology can pre‑assemble high‑value minerals under mild conditions. Whether that becomes an industrial pathway depends on scale, separation, and safeguards. But in a world racing to decarbonize — and wrestling over who controls REEs — this discovery adds a fresh, plant‑powered option to the toolkit. PubMed