Coccoloba gigantifolia (Polygonaceae) is a newly described plant species from the Brazilian Amazon. It reportedly has the largest leaves in the world! These leaves were measured at >200 cm in length.

Botanists from the National Institute of Amazonian Research (INPA) in Manaus, Brazil first encountered an individual of the unknown Coccoloba tree in 1982 while surveying the Madeira River Basin in the Brazilian Amazon.

They spotted more individuals of the plant over subsequent expeditions in the 1980s. But they couldn’t pinpoint the species at the time.

The individual trees weren’t bearing any flowers or fruits then, parts that are essential to describing a plant species, and their leaves were too large to dehydrate, press and carry back to INPA. The researchers did take notes and photographs.

In 1993, botanists managed to finally collect two large leaves from a tree in the state of Rondônia, which they then framed for public viewing at INPA.

“The species became locally famous, but due to the lack of reproductive material it could not be described as a new species for science,” Rogério Gribel, a researcher at INPA, told Mongabay in an email.

It was more than a decade later, in 2005, that Gribel and his colleague, Carlos Alberto Cid Ferreira, collected some seeds and dying flowers from a tree in Jamari National Forest.

Again, these materials weren’t good enough to describe the plant species. So they sowed the seeds at the INPA campus, grew the seedlings, and waited. Their patience bore fruit 13 years later. Literally.

The researchers say that C. gigantifolia, which grows to about 15 meters (49 feet) in height and has leaves that can reach 2.5 meters (8 feet) in length, likely has the largest known leaf among dicotyledonous plants — a large group of flowering plants that include sunflowers, hibiscus, tomatoes and roses.

These plants have seeds that can be split into two identical halves, each forming the first two embryonic leaves of the seedling, and their leaves generally have branched veins. The seeds of monocotyledonous plants, by contrast, give out a single embryonic leaf and the grown plants’ leaves have parallel veins, such as those of palm trees, grasses, orchids and bananas.

“Comparing leaf size between species is often difficult as there is a large individual variation in leaf size within the same species,“Gribel said. “It is possible that this leadership of Coccoloba gigantifolia will be challenged in the future. For example, species of Gunnera, a genus of wide distribution worldwide, also exhibit huge leaves. But the Gunnera species are not arboreal.“

Although C. gigantifolia has been known in the public and the scientific community for nearly four decades, describing it formally and giving it an official name was an essential step to complete.

“A known but undescribed species is like a person without a birth certificate or ID; it is like a person who does not formally have their identity recognised,” Gribel said. “For example, in Brazil there is currently a major effort by the scientific community to catalogue the national flora. Although known for many years, Coccoloba gigantifolia could not so far be added to the Brazilian Plant List by the scientists participating of this great initiative.”

Without a formal identity, it’s also difficult to assess the plant’s conservation status. “Initiatives to prevent its extinction are also impaired if the plant has no scientific name,” Gribel said. “Similarly, measures to regulate collection, trade, transport, planting, etc. depend on species recognition as a single taxonomic entity.”

As shown in the satellite data, these areas have experienced heavy deforestation over the past couple decades.

“The middle and low stretches of the Madeira River still have much of their forest conserved but deforestation has been growing rapidly in these areas especially in northeastern Rondônia and southern Amazonas,” Gribel said. “The Samuel Dam in the Jamari River (and possibly the Santo Antonio and Jirau Dams in the Madeira River) flooded tens of thousands of hectares of forests with Coccoloba gigantifolia and may have negatively affected the populations. The ongoing paving of the BR319 highway will increase deforestation throughout the Middle and Lower Madeira region.”

Moreover, the level of water is constantly increasing in the region, probably increasing the ‘pressure’ on Coccoloba gigantifolia.

The authors have recommended listing the new tree species Coccoloba gigantifolia as endangered on the IUCN Red List. Monga Bay

Reference ~ https://strangesounds.org/2019/12/new-tree-species-giant-leaves-brazil-amazon-photo-video.html

Melo, E. D., Ferreira, C. A. C., & Gribel, R. (2019). A new species of Coccoloba P. Browne (Polygonaceae) from the Brazilian Amazon with exceptionally large leaves. Acta Amazonica, 49(4), 324-329.