Researchers from BRIT and the United Kingdom Untangle the Mystery of the Evil Tribe

The National Science Foundation (NSF) and Natural Environment Research Council (NERC) have awarded botanists at the Fort Worth Botanic Garden | Botanical Research Institute of Texas (FWBG | BRIT) and Royal Botanical Gardens, Kew $1.2 million (nearly $850,000 from NSF and nearly £300,000 from NERC) to classify and understand plants in a hyper-diverse group referred to as “ironweeds” in the sunflower family, Compositae. This is the first grant of its kind awarded to FWBG | BRIT and Kew through a special international collaborative program between NSF and NERC.

This group of plants forms what plant taxonomists refer to as the Vernonieae tribe and includes approximately 1,500 species of herbs, shrubs, trees and vines worldwide. The “ironweeds” have confounded botanists attempting to understand patterns shared by species in this group, which has led experts to describe tribe Vernonieae by a notorious nickname: the “evil tribe.”

“Vernonieae is incredibly confusing. The characteristics among many species overlap and vary to a degree that it’s hard to differentiate them as distinct genera,” said FWBG | BRIT Research Botanist and Principal Investigator (PI), Morgan Gostel. “At the same time, other plants in the tribe are highly distinctive with little in common and are quite easy to recognize and distinguish at the taxonomic level of genus.”

“For most of the history of Vernonieae, more than one thousand species were classified in the same genus (Vernonia), but Vernonia has been reduced to just 20 species. This has left the remaining species of this once vast genus in a state of limbo or ‘purgatory’ until taxonomists determine their correct placement,” Gostel said.

Recently, considerable research in the Americas has begun to unravel the mysteries of the tribe and species formerly placed in the genus Vernonia; however, nearly half of the species of Vernonieae are restricted to the Eastern Hemisphere and have been long neglected by botanists, said Gostel. Funding from this NSF-NERC award will allow Dr. Gostel and his collaborators at Kew to reclassify diversity in Vernonieae from the Eastern Hemisphere and develop tools to help others identify and understand this enigmatic group of plants. Members of the team at Kew include Drs. Isabel Larridon, Benoit Loeuille and Ana Rita Simões.

Taxonomic knowledge like this is essential to conserving the diversity of plant life on the planet, said Royal Botanic Gardens, Kew Research Leader and co-PI for the grant, Dr. Isabel Larridon. “Understanding the diversity of the nearly half-a-million plant species on Earth is a strategic priority for Kew Science,” Larridon said. “Yet there are too many plant species and not enough trained taxonomists to study, describe and distribute information about them.”

While resolving questions about Vernonieae, Gostel and Larridon will also advance the distribution of scientific information and the training of the next generation of scientists.

The results of their work will be added to the newly established Global Compositae Database (GCD), a public online taxonomic resource for the Compositae family. The GCD, coordinated by the International Compositae Alliance (TICA) is part of a global effort to develop an online database of all plant life and recognized as a Taxonomic Expert Network by the World Flora Online.

At the same time, the team will train the next generation of plant taxonomists by working with at least three graduate students and four undergraduate students. Further international training will be provided through workshops with students, botanists and herbarium and university staff and via environmental education programs offered by FWBG | BRIT and Kew.

During the four-year project, Gostel, Larridon and their team will conduct field work in five countries critical to sampling for this work (the Democratic Republic of the Congo, Madagascar, Mozambique, South Africa and Thailand) and study plant specimens in numerous herbaria around the world, most notably at the Royal Botanic Gardens, Kew (K); Fort Worth Botanic Garden|Botanical Research Institute of Texas (BRIT), Missouri Botanical Garden (MO), Muséum National d’Histoire Naturelle in Paris (P), and Botanic Garden Meise (BR). They will analyze the DNA of Vernonieae and the morphological features such as small hairs, pollen and flowers from these plant species to identify patterns that can help them classify diversity in the group.

“By better understanding Vernonieae, we will be making great strides in understanding the complexity of this group and making important discoveries that will help botanists understand and communicate about plant diversity in other groups,” Gostel said. “We expect the ‘evil tribe’ won’t be so evil when we’re done.”

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