New Amazonian Cycad Species Survives Permanently Flooded Forests

Scientists have discovered a new Amazonian species belonging to an ancient cycad lineage. This newly identified plant survives throughout the year in permanently flooded forests, including when part of its stem is beneath the water.

Its remarkable ability to persist in oxygen-deprived swamps broadens the known habitats of these ancient seed plants and increases the urgency of protecting the wetlands on which they depend.

Life in flooded forests

Within the permanently inundated forests of Peru’s northern Loreto region, the newly discovered cycad was found anchored in water-saturated ground that would prevent most related species from surviving.

While carrying out fieldwork in 2025, Dr Ricardo Zarate-Gomez of the Peruvian Amazon Research Institute (IIAP) recorded healthy plants with their lower stems underwater, demonstrating that this lineage can endure an environment previously considered unsuitable for it.

Whereas other members of this group require freely drained soils, the species continued to survive in ground that remains saturated all year.

This highly specialised habitat restricts its known distribution and raises questions about how it copes with unceasing flooding.

Cycad built for low oxygen

Floodwater fills the air spaces in soil, leaving roots without sufficient oxygen and causing them to die. Most terrestrial plants cannot withstand waterlogged soil, instead ceasing growth or developing root rot.

A review published in 2008 explained that flooded soil pores leave plant cells producing energy with very little oxygen available.

Unlike most seed plants from this lineage, the new species maintained living tissues even when water surrounded the base of its stem.

This resilience allows it to inhabit swamps with no dry periods, but also makes it dependent on wetlands that are frequently drained by people.

Inside an ancient lineage

Taxonomists gave the plant the name Zamia urarinorum, with its distinguishing features set out in a formal description.

Among cycads – seed plants characterised by rigid leaves and cones – the genus Zamia is generally found on well-drained tropical land.

Fossil evidence and a 2015 analysis showed that cycad evolutionary history extends back more than 200 million years.

Describing cycads as living fossils may be misleading, but their lineages were present when dinosaurs lived, while modern species diversified later.

Zamia, a name with meaning

Named after the Urarina people, Zamia urarinorum was discovered on Indigenous territory between the Tigrillo and Urituyacu Rivers in Loreto.

Local stewardship preserved the wetlands sufficiently for IIAP teams to conduct their work there, while also allowing the plant species to endure.

Residents of villages including Raya Yacu, Nuevo Horizonte and Puerto Rico led visits and assisted scientists in documenting the locations where the plants occur.

Giving the scientific name a connection to a living community made it more difficult to separate the discovery from decisions about long-term protection.

Cycad reproduction limits

The seeds are held in cone-like structures, and researchers found that the cones and seeds were both smaller than those of closely related species.

As male and female plants occur on separate individuals, reproduction requires both sexes to grow near enough to one another within the same habitat.

Small populations may decline unnoticed if logging or flooding eliminates one sex, leaving fertile individuals without a nearby partner.

Mapping a new cycad range

By comparing plant collections with digital records, researchers distinguished Zamia urarinorum from comparable species and established where its closest relatives occur.

Because similar leaves can conceal substantial distinctions, botanists examined leaf characteristics and reproductive structures before defining the new distribution boundaries.

Many Zamia populations across Amazonian wetlands and uplands have yet to be thoroughly studied, creating gaps in knowledge about the distribution of each species.

Improved maps enable planners to avoid important locations and support future searches for plants concealed in difficult-to-access swamps.

Carbon in the wetlands

Wetland forests reduce the speed of floodwaters and retain carbon in saturated soils, meaning their loss can increase emissions and alter rivers.

In peatlands – wetlands in which dead vegetation accumulates as dense peat rather than decomposing – permanent saturation delays decay and stores carbon for centuries.

A 2014 paper calculated that Peru’s Pastaza-Marañón peat basin contains roughly 3.5 billion tons of carbon.

Safeguarding a rare plant in flooded forests also means conserving the swamp soils that prevent carbon from reaching the atmosphere.

Threats to cycads

Agricultural drainage, oil spills and new roads can drive wetland forests towards collapse before scientists have completed their surveys.

Reducing water tables dries the ground and accelerates decomposition, while pollution may cover roots and restrict the limited oxygen that remains available.

Given its restricted known range in Loreto, the team cautioned that the species could already be endangered before it receives a formal assessment.

If safeguards are not introduced promptly, this discovery may become a record of a species already disappearing from view.

Risk and reality

Conservation planning commonly begins with the IUCN, a global organisation that evaluates extinction risk, and the authors called for rapid protection.

Under IUCN criteria, assessors consider distribution size, population decline and threats before applying categories such as “Endangered.”

“This finding positions our country as a leader in botanical research of tropical humid ecosystems,” IIAP scientists said.

Effective protection will rely on local regulations and enforcement, as an IUCN classification alone cannot prevent land conversion.

Research and conservation

The discovery of Zamia urarinorum in flooded forests connected deep plant evolutionary history, exceptional survival biology and a wetland landscape facing pressure.

Further research could identify additional populations and examine its oxygen tolerance in greater detail, while conservation action will determine whether these wetlands remain intact.