Unobtrusive green plants grow in one of the most lush places on Earth. Scientists have been puzzled for 50 years by the strange mix of features that the plant displays, even though it was long used by the Indigenous Machiguenga.
Robin Foster, Smithsonian Institution botanist, said that the plant was not special except that it had the characteristics of several plant families. The plant was first collected by Foster in 1973.
"I can usually tell my family by looking at them, but I'm not sure if this one is mine."
This mysterious plant grows in the Manu river floodplain forest and bears either male or female flowers. It's decorated with delicate, small, bright orange fruits that are shaped like paper lanterns during the dry and wet seasons.
The fruit. (CE Timothy Paine/Thomas et al. Taxon, 2021
Even this plant's unique bounty, which is sweet and creamy, wasn't enough to help us figure out the place this bizarre species was on the tree. Foster showed the samples of the plants to scientists who were so baffled that they couldn't even figure out which plant family this strange species should belong to.
Nancy Hensold, Field Museum botanist, recalled that she tried to identify it using technical characters such as boiling the flowers' ovaries and taking photos of the pollen. But, after all this, we still didn’t know." It really bothered me.
Initial attempts at analyzing the DNA of the dried specimens were unsuccessful due to the fact that the genetic material was too damaged. Patricia Loayza, Manu National Park ecologist, had obtained fresher samples.
Picramniaceae is a family of neotropical plant families. It was finally discovered by gene analysis from the nucleus and chloroplasts.
"My initial reaction was, "What the hell?"" Wayt Thomas, curator at The New York Botanical Garden. "These plants were unlike any other in the family."
Its flowers have some similarities to Nothotalisia (also from the Picramniaceae) but the fruit and green bits of this plant are quite different.
These, together with the genetics, support that this plant is part of an entirely new genus. The researchers have named it Aenigmanu which means "mystery about Manu".
Thomas and his colleagues gave the plant the name alvareziae in honor of lvarez Loayza, who pioneered ecology, teaching, and conservation.
"Now that it has been classified in Picramniaceae we know to search for secondary compounds of potential use anti-cancer drugs which are a feature in this family," Martin Cheek, London's Royal Botanic Garden taxonomist, said to The CNN Wire.
Researchers recommend that Aenigmanu Alvareziae be considered endangered because of the habitat it was found in.
"Plants are not well-studied. Particularly tropical forest plants. Particularly Amazon plants. Foster said that Amazon plants are especially important.
"To understand the changes occurring in the tropics and to protect what remains and to restore areas that were destroyed, plants are essential to all that lives there.
Taxon published this research.
