Redefining genera across the legume subfamily Caesalpinioideae in latest PhytoKeys issue

The Special Issue features 16 papers by 54 authors from 13 countries and forms Part 14(1) of the Advances in Legume Systematics Series.

Blog post by Colin Hughes, University of Zurich

The three most important taxonomic ranks used to classify organisms are family, genus and species, especially the latter two, which make up the scientific binomials used to communicate about biodiversity, and indeed about all aspects of biology. While the description of a new plant family is now a very rare event, the same is not true for genera. Indeed, delimitation of genera within many plant families remains in a state of considerable flux, because many traditionally recognized genera do not correspond to evolutionary groups. This causes unwelcome instability in scientific names of species and is why work to delimit genera lies at the heart of much current research in systematic botany.

This is very much the case for subfamily Caesalpinioideae, the second largest subfamily of the legume family, which is the focus of this new special issue of the open-access, peer-reviewed journal PhytoKeys. With around 4,600 species of mostly trees, shrubs and lianas, distributed right across the tropics in rainforests, dry forests and savannas, Caesalpinioideae represent a spectacularly diverse lineage of tropical woody plants.

New analyses of DNA sequences of 420 species of Caesalpinioideae presented here reveal that 22 of the 152 currently recognized genera do not coincide with natural evolutionary groups, i.e., in phylogenetic terms, they are non-monophyletic. The aim of this special issue is to re-define as many of these problematic genera as possible in order to bring them into line with natural evolutionary lineages. To achieve this, nine new genera of Caesalpinioideae are described, five previously recognized genera are resurrected, and three genera shown to be nested within other genera are consigned to synonymy.

Many of the species in these new genera are important, conspicuous, ecologically abundant, and, in some cases, geographically widespread trees in tropical forests. For example, the three species of the new genus Osodendron  are important large canopy trees in tropical rain forests and riverine gallery forests across a broad swathe of west and central Africa. In recent decades these species have been successively placed in different genera including Cathormion, Samanea and Albizia, among others. The neglected generic placement of these African trees has finally been resolved via analyses of DNA sequences, and a new generic home for them has been established.

In contrast, two of the genera newly described in this special issue, Mezcala  and Boliviadendron, each with just a single species, are much more elusive plants occupying very narrowly restricted geographical ranges. Mezcala occurs across just a few square km of the central Balsas Depression in south-central Mexico and Boliviadendron is known from just two interior valleys of the Bolivian Andes. Establishing these two lineages as distinct genera highlights the importance of conserving these globally rare evolutionary lineages.

Choosing names for new taxa is one of the delights and privileges of the practising taxonomist. Derivations of the names of the nine new genera described in this special issue span features of the plants themselves and the locations where they grow, as well as names of fellow legume researchers honoured with genera named in recognition of their contributions. For example, Osodendron is named after ‘Oso’ a food that is prepared in West Africa from seeds of one of the species now placed in the new genus. Mezcala is named for the indigenous Mezcala culture of the Balsas region in Mexico where the genus is found. Boliviadendron is named as such because it is a tree that grows in Bolivia and nowhere else. The new genus name Heliodendron is derived from the Greek helios (sun) and dendron (tree) because it grows in the sunshine state of Queensland in Australia and its flowers are arranged in sun-like globose heads.

Leaves and fruits of the new genus Naiadendron from Amazonian rainforest. Photo by Glocimar Pereira-Silva

Finally, Naiadendron celebrates the Brazilian Amazon where the genus grows, and the famous German botanist Carl Friedrich Philipp von Martius (1794–1868), who named the Brazilian Amazon after the Naiads, Greek mythology’s nymphs of freshwater.

Four of the genera newly described in this Special Issue are named after prominent contemporary legume taxonomists, three women and one man: Gretheria for Rosaura Grether, a Mexican specialist on the genus Mimosa, Ricoa  for Lourdes Rico, another Mexican botanist who worked on legumes based at Kew, Marlimorimia, in honour of Marli Pires Morim of the Jardim Botânico do Rio de Janeiro, Brazil in recognition of her contributions to the taxonomy of mimosoid legumes, and Gwilymia named for Gwilym Lewis, in honour of one of the world’s most experienced and productive legume taxonomists who is legume research leader in the Herbarium at the Royal Botanic Gardens, Kew.

One of the central achievements of the work on Caesalpinioideae presented in this Special Issue is that for the first time a truly pantropical analysis of this large group of plants has been accomplished. A global synthesis is essential to work out how many genera there are.

For example, by sampling across Asia, Africa, Madagascar, North and South America, it has become clear that the Old World species of the important pantropical genus Albizia are not closely related to Albizia in the Americas, prompting splitting of the genus and resurrection of the name Pseudalbizzia for the New World species. All elements of the former Albizia – the last so-called ‘dustbin’ genus in the mimosoid legumes – are accounted for in this special issue (here, here and here). Similarly, the genus Prosopis, one of the most important silvopastoral tree genera of the dryland tropics, has traditionally encompassed elements spanning the New and Old Worlds that are here shown to comprise four distinct evolutionary lineages, two in the Old World and two in the Americas, here treated as four separate genera.

Changes to the scientific names of species are not always immediately welcomed by users, but over time, establishment of a classification that is based on robust evidence about evolutionary history will result in greater nomenclatural stability and in named taxa that are aligned with natural groups and hence biologically more informative. This special issue, reshaping the generic system of a species-rich group of legumes, is an important step towards that goal.

Photo credits: Globimar Pereira-Silva, Steen Christensen, William Hawthorne, Colin Hughes, Luciano de Queiroz, Marcelo Simon.

Plants quick to let their flowers fade for protection, show new field experiments and microbiome

Microbes growing on flowers have adverse effects on their fruit yields. This is why plants are quick to shed their flowers, reveals a new study involving both field experiments and plant microbiome analyses.

The present study looked into the wild ginger in Japan (Alpinia japonica, Zingiberaceae). Its flowers open in the morning and wither around sunset, as many one-day flower plants do.
Photo by Shoko Sakai.

Microbes growing on flowers have adverse effects on their yields. This is why plants are quick to shed their flowers, reveals a new study involving both field experiments and plant microbiome analysis.

The findings – made by a joint team of researchers from the Centre for Research on Ecology and Forestry Applications (CREAF, Spain) and Kyoto University (Japan) – are published in the open-access scholarly journal Metabarcoding and Metagenomics.

Scientifically speaking, flowers are a reproductive structure of a plant. Unlike mammals, though, perennial plants develop those de novo every season and only retain them for as long as needed.

While a few earlier studies have already looked into the variation in flower lifespan among species, they were mainly concerned with the tradeoff between plants spending energy on producing and maintaining their flowers, and the benefit they would achieve from retaining their reproductive organs.

Most flowers complete their role and wither or drop within only several days or even less.
Photo by Shoko Sakai.

Prior to the present study, however, the team found another perspective to look at the phenomenon: why did plants invest their energy –  even if the ‘cost’ was minimal – to produce fragile flowers that would wither in a matter of days, rather than investing a bit more of it to produce a lot more durable ones, thereby increasing their reproductive success?

“Interestingly, flower lifespan is negatively correlated with temperature; the hotter the environment where they bloom, the shorter the period a plant retains them. The phenomenon has been known for a long time.

Then, at some point, I came up with the hypothesis that antagonistic microbes, such as bacteria and fungi growing on flowers after the flower bud opens, must be the driver that shortens the lifespan of a flower. I doubted that it was a coincidence that microbes grow faster in higher temperatures,”

comments Shoko Sakai, author of the present study.

Flowers provide various habitats for microbes. They attract pollinators by secreting nectar, which is rich in sugars, and often contains other nutrients, such as amino acids and lipids. The stigma is a germination bed for pollen grains connected to a growth chamber for pollen tubes. It maintains humidity and nutrients necessary for pollen tube growth. Not surprisingly, abundance of the microbes increases over time on individual flowers after it opens.

Before jumping to their conclusions, the scientists set out to conduct field experiments to see what microbial communities would appear on flowers if their longevity was prolonged.

To do this, they took microbes from old flowers of wild ginger (Alpinia japonica) – a species found in Japan and blooming in the early summer when the hot and humid weather in the country is ideal for microbial growth. Then, they transferred the microbes to other wild ginger plants, whose flowers had just opened.

In line with their initial hypothesis, the research team noted that the plant produced significantly fewer fruits, yet there were no visible symptoms on the flowers or fruits to suggest a disease. However, an analysis of the plants’ microbiomes revealed the presence of several groups of bacteria that were increasing with time. As these bacteria can also be found on the flower buds of flowers that have not been treated, the bacteria is categorised as “resident” for the plant.

“So far, flower characteristics have mostly been studied in the context of their interactions with pollinators. Recent studies have raised the question whether we have overlooked the roles of microbes in the studies of floral characteristics.

For example, flower volatiles – which are often regarded as a primary pollinator attractant – can also function to suppress antagonistic microbes. The impacts of microbes on plant reproductive ecology may be more deeply embedded in the evolution of angiosperms than we have considered,”

Sakai concludes.
Flowers have various organs rich in nutrients, and each organ harbours a distinct microbiome. Flower visitors transfer microbes between and within flowers.
Photo by Shoko Sakai.

***

Research article:

Jiménez Elvira N, Ushio M, Sakai S (2022) Are microbes growing on flowers evil? Effects of old flower microbes on fruit set in a wild ginger with one-day flowers, Alpinia japonica (Zingiberaceae). Metabarcoding and Metagenomics 6: e84331. https://doi.org/10.3897/mbmg.6.84331

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Follow the Metabarcoding and Metagenomics (MBMG) journal on Twitter and Facebook (@MBMGJournal).

Underground carnivore: the first species of pitcher plant to dine on subterranean prey

This is the first pitcher plant known to produce functional underground traps, and the first for which capture of subterranean prey has been observed.

What we thought we knew about carnivorous plants was swiftly called into question after scientists discovered a new species in the Indonesian province of North Kalimantan, on the island of Borneo. Nepenthes pudica is what scientists call a pitcher plant – it has modified leaves known as pitfall traps or pitchers, where it captures its prey. In a strategy so far unknown from any other species of carnivorous plant with pitfall traps, this one operates underground, catching its prey in the soil.

Habitat with a mature plant of Nepenthes pudica lacking pitchers on the aboveground shoot. Photo by Martin Dančák

“We found a pitcher plant which differs markedly from all the other known species,”

says Martin Dančák of Palacký University in Olomouc, Czech Republic, lead author of the study, published in the journal PhytoKeys, where his team described the new species.

“In fact, this species places its up-to-11-cm-long pitchers underground, where they are formed in cavities or directly in the soil and trap animals living underground, usually ants, mites and beetles”, he adds.

A completely buried shoot with a bunch of well-developed pitchers uncovered from beneath a moss cushion. Photo by Martin Dančák

Only three other groups of carnivorous plants are known to trap underground prey, but they all use very different trapping mechanisms and, unlike Nepenthes pudica, can catch only minuscule organisms.

The plant forms specialised underground shoots with entirely white, chlorophyll-free leaves. In addition to lacking their normal green pigmentation, the leaves supporting the pitchers are reduced to a fraction of their normal size. The pitchers, however, retain their size and often also their reddish colour.

If no cavity is available, the shoots grow directly into the soil, as seen here where a bunch of pitchers was excavated from the ground. Photo by Martin Dančák

“Interestingly, we found numerous organisms living inside the pitchers, including mosquito larvae, nematodes and a species of worm which was also described as a new species”,

explains Václav Čermák of the Mendel University in Brno, Czech Republic, who was also part of the research team.

The newly discovered species grows on relatively dry ridge tops at an elevation of 1100–1300 m. According to its discoverers, this might be why it evolved to move its traps underground. “We hypothesise that underground cavities have more stable environmental conditions, including humidity, and there is presumably also more potential prey during dry periods,” adds Michal Golos of the University of Bristol, United Kingdom, who also worked on this curious plant.

A shoot with reduced white leaves and well-developed pitchers extracted from a cavity under a tree. Photo by Martin Dančák

A series of lucky events back in 2012 led to the discovery of the species. Ľuboš Majeský of Palacký University Olomouc, part of the research team, recounts the key moment: “During a several-day trip with our Indonesian colleagues to a previously unexplored mountain, randomly chosen from a number of candidates, we noted plants which were undoubtedly Nepenthes but produced no pitchers. After a careful search, we found a couple of aerial pitchers, a few juvenile terrestrial ones, and one deformed pitcher protruding from the soil.”

“At first, we thought it was an accidentally buried pitcher and that local environmental conditions had caused the lack of other pitchers. Still, as we continued to find other pitcherless plants along the ascent to the summit, we wondered if a species of pitcher plant might have evolved towards loss of carnivory, as seen in some other carnivorous plants. But then, when taking photos, I tore a moss cushion from a tree base revealing a bunch of richly maroon-coloured pitchers growing from a short shoot with reduced leaves entirely lacking chlorophyll.”

The group then checked the other encountered plants and found that all of them had underground shoots with pitchers, confirming that this species specifically targets the underground environment.

The scientific name Nepenthes pudica points to the plant’s curious behaviour: it is derived from the Latin adjective pudicus, which means bashful and reflects the fact that its lower pitchers remain hidden from sight.

Nepenthes pudica is endemic to Borneo.

“This discovery is important for nature conservation in Indonesian Borneo, as it emphasises its significance as a world biodiversity hotspot. We hope that the discovery of this unique carnivorous plant might help protect Bornean rainforests, especially prevent or at least slow the conversion of pristine forests into oil palm plantations,”

concludes Wewin Tjiasmanto of Yayasan Konservasi Biota Lahan Basah, who helped discover the new species.

***

Research article

Dančák M, Majeský Ľ, Čermák V, Golos MR, Płachno BJ, Tjiasmanto W (2022) First record of functional underground traps in a pitcher plant: Nepenthes pudica (Nepenthaceae), a new species from North Kalimantan, Borneo. PhytoKeys 201: 77-97. https://doi.org/10.3897/phytokeys.201.82872

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A provisional checklist of European butterfly larval foodplants

For the first time, a list of the currently accepted plant names utilised by 471 European butterfly larvae is presented, with references.

Guest blog post by Harry E. Clarke, Independent Researcher

5th instar Swallowtail larvae feeding on Milk-parsley.

Many books on butterflies publish lists of their larval foodplants. However, many of these lists of larval foodplants have been copied from previous lists, which in turn have been copied from previous lists. Consequently, errors have crept in, and many plant names have long been superseded. This can result in duplicates in the list, with the same plant being given two different names. Most plant lists do not include the authority, which can make it difficult or impossible to identify which plant is being referred to. Some of these plants may not be used by butterflies in Europe, but elsewhere in their range. Or the plants may have been used in breeding experiments, but not used by the butterflies in the wild.

Many of these publications providing the larval foodplants of butterflies only provide the binomial name, without specifying the author. This can create problems in knowing which species of plant is being used, as the same plant name has been used in the past by different authors to describe different species. In some cases, distribution can be used to determine the correct species, but plants can often have similar distributions. For example, in the World Checklist of Vascular Plants, there are 40 entries for the plant with the scientific name Centaurea paniculata, which refer to thirteen different accepted species, depending on authors, subspecies, and variety or form.

Not quite so simple: updating the current lists of larval foodplants

With climate change and habitat loss threatening numerous species, the conservation of butterflies (and other animals) is becoming more important. Whilst many factors determine the distribution of butterflies, such as temperature and rainfall, their survival depends solely on the kinds of plants their larvae eat. Accurate lists of larval foodplants are therefore important to find out where to direct limited conservation resources for the best result.

What started out as a straightforward job of updating the existing lists of larval foodplants with currently accepted names turned out to be a far bigger job. Many of the lists are incomplete, and may vary throughout the range of the butterfly. Here, errors have crept in too. Many references provide incomplete, unverifiable information. Many species of butterfly lay their eggs off-host, rather than on the host plant. For example, the Silver-washed Fritillary (Argynnis paphia)oviposits on tree trunks above where Viola species are growing. Consequently, oviposition records need to be treated with caution, depending on the species.

What do butterfly larvae eat, and why does it matter?

Butterfly larvae can be very fussy about which plants they can use. 20% of European butterfly larvae are monophagous, feeding on just one species of plant. 50% are oligophagous, feeding on a few different closely related plants, whilst 30% are polyphagous feeding on plants in many different families. The Holy Blue (Celastrina argiolus) can utilise plants in an astonishing 19 different families.

The oligophagous butterflies can be divided into two groups:

  • Oligophagous-monophagous (OM) – feeding on one plant species in one region, and another species in another region.
  • Oligophagous-polyphagous (OP) – feeding on several closely related species of plants throughout their range, usually in the same genus, or a closely related genus.
4th instar Small Tortoiseshell feeding on Common Nettle.

Plant preferences are only known for a few species of butterflies. For example, the English race of the Swallowtail (Papilio machaon) feeds on Milk-parsley (Peucedanum palustre), whereas in the rest of Europe it has been recorded on 62 other plants. The main larval foodplant of the Small Tortoiseshell (Aglais urticae) is Common Nettle(Urtica dioica), although it will occasionally use other plants.

The survivability of larvae on different plants is largely unknown, except in a few cases where the butterfly species has been studied in detail. There are plants that larvae may be able to eat, but that would likely not help them survive to pupation.

Two species are known to switch their larval foodplant during their second year of development. The Scarce Fritillary (Euphydryas maturna),for example, switches from Ash (Fraxinus excelsior) to Guelder-rose (Viburnum opulus). The Northern Grizzled Skipper (Pyrgus centaureae) switches from Dwarf birch (Betula nana) to Cloudberry (Rubus chamaemorus).

The most delicious plants

For the first time, a list of the current accepted plant names utilised by 471 European butterfly larvae is presented, with references. Where possible, errors in previous lists have been removed. The list of larval foodplants doubled compared to previous published lists. This has resulted in a list of 1506 different plant species in 72 different families. 86 plant records are only known at the generic level. Larval foodplants of 25 butterfly species are currently unknown, which are mostly the “Browns” (Satyrinae), which probably feed on grasses (Poaceae), or possibly sedges (Cyperaceae).

Whilst most plant families are utilised by less than six butterfly species, a few plant families are particularly favoured, with grasses (Poaceae) and legumes (Fabaceae) being the most popular. Similarly, most plant species are only utilised by a few butterfly species, but the fine grasses Sheep’s Fescue (Festuca ovina) and Red Fescue (Festuca rubra) are favoured by a large number of butterfly species.

Taxonomic splits create problems. Where cryptic species are allopatric, records can be allocated on the basis of their distribution. But where cryptic species are sympatric, this will require a resurvey to determine the larval foodplants. It cannot be assumed that two cryptic butterfly species use the same plants, as something has to become different for them to evolve into separate species.

Looking forward

Future publications should ensure that old and ambiguous plant names are not used. Plant names should be specified with their full scientific name, as specified by the International Code of Nomenclature for algae, fungi, and plants. The World Checklist of Vascular Plants should be checked to ensure the currently accepted plant name is being used.

Fully documented records are needed of what larval foodplants butterfly larvae are utilising in the wild. To get a better understanding of usage, full details need to be recorded, including date, location, altitude, abundance, and larval stage. Abundance will help in the understanding of preferences. To allow records to be properly verified, evidence should be provided on how the larvae and plants were identified. Regional lists are also important – to help direct conservation efforts to the plants being used locally, rather than elsewhere. This list of larval foodplants is provided as a step towards a fully justified database, which will be updated as and when corrections are found. It highlights those 25 butterfly species whose larval foodplants are currently unknown.

4th instar Chequered Skipper (Carterocephalus palaemon) larvae feeding on Purple Moor-grass (Molinia caerulea).

Research article:

Clarke HE (2022) A provisional checklist of European butterfly larval foodplants. Nota Lepidopterologica 45: 139-167. https://doi.org/10.3897/nl.45.72017

Lost South American wildflower “extinctus” rediscovered (but still endangered)

Long believed to have gone extinct, Gasteranthus extinctus was found growing at Bosque y Cascada Las Rocas, a private reserve in coastal Ecuador.

Scientific names get chosen for lots of reasons: they can honor an important person, or hint at what an organism looks like or where it’s from. For a tropical wildflower first described by scientists in 2000, the scientific name “extinctus” was a warning. The orange wildflower had been found 15 years earlier in an Ecuadorian forest that had since been largely destroyed; the scientists who named it suspected that by the time they named it, it had already become extinct. But in a new paper in PhytoKeys, researchers report the first confirmed sightings of Gasteranthus extinctus in 40 years.

Long believed to have gone extinct, Gasteranthus extinctus was found growing next to a waterfall at Bosque y Cascada Las Rocas, a private reserve in coastal Ecuador containing a large population of the endangered plant. Photo by Riley Fortier.

Extinctus was given its striking name in light of the extensive deforestation in western Ecuador,” says Dawson White, a postdoctoral researcher at Chicago’s Field Museum and co-lead author of the paper. “But if you claim something’s gone, then no one is really going to go out and look for it anymore. There are still a lot of important species that are still out there, even though overall, we’re in this age of extinction.”

The bright orange flowers of the Ecuadorian cloud forest herb Gasteranthus extinctus, long believed to have gone extinct, light up the forest understory as if begging to be seen. Photo by Riley Fortier

The rediscovered plant is a small forest floor-dweller with flamboyant neon-orange flowers. 

“The genus name, Gasteranthus, is Greek for ‘belly flower.’ Their flowers have a big pouch on the underside with a little opening top where pollinators can enter and exit,” says White.

Photo by by Riley Fortier

G. extinctus is found in the foothills of the Andes mountains, where the land flattens to a plane that was once covered in cloud forest. The region, called the Centinela Ridge, is notorious among biologists for being home to a unique set of plants that vanished when its forests were almost completely destroyed in the 1980s. The late biologist E. O. Wilson even named the phenomenon of organisms instantly going extinct when their small habitat is destroyed “Centinelan extinction.”

Part of the team departs the field for the day with bags full of rare plant specimens, surrounded by the typical Centinelan landscape of tall, remnant trees scattered across pasture and farmland. Photo by Dawson White

The story of Centinela was also an alarm to draw attention to the fact that over 97% of the forests in the western half of Ecuador have been felled and converted to farmland. What remains is a fine mosaic of tiny islands of forest within a sea of bananas and a handful of other crops.

Sunset on the peak of Centinela Ridge in coastal Ecuador, near to where the first collections of the endangered wildflower Gasteranthus extinctus were made some 40 years ago. Photo by Nigel Pitman

“Centinela is a mythical place for tropical botanists,” says Pitman. “But because it was described by the top people in the field, no one really double-checked the science. No one went back to confirm that the forest was gone and those things were extinct.”

Part of the team that rediscovered Gasteranthus extinctus traverses steep ravines in the forests of coastal Ecuador in search of rare plants. From left: Washington Santillán, Sr. Hermogenes, Alix Lozinguez, and Nicolás Zapata. Photo by Thomas L.P. Couvruer

But around the time that Gasteranthus extinctus was first described in 2000, scientists were already showing that some victims of Centinelan extinction weren’t really extinct. Since 2009, a few scientists have mounted expeditions looking for G. extinctus was still around, but they weren’t successful. When White and Pitman received funding from the Field Museum’s Women’s Board to visit the Centinela Ridge, the team had a chance to check for themselves. 

Starting in the summer of 2021, they began combing through satellite images trying to identify primary rainforest that was still intact (which was difficult, White recalls, because most of the images of the region were obscured by clouds). They found a few contenders and assembled a team of ten botanists from six different institutions in Ecuador, the US, and France, including Juan Guevara, Thomas Couvreur, Nicolás Zapata, Xavier Cornejo, and Gonzalo Rivas. In November of 2021, they arrived at Centinela.

A sign points out the community of Centinela del Pichincha in coastal Ecuador, likely the namesake of the Centinela Ridge. Photo by Nigel Pitman

“It was my first time planning an expedition where we weren’t sure we’d even enter a forest,” says Pitman. “But as soon as we got on the ground we found remnants of intact cloud forest, and we spotted G. extinctus on the first day, within the first couple hours of searching. We didn’t have a photo to compare it to, we only had images of dried herbarium specimens, a line drawing, and a written description, but we were pretty sure that we’d found it based on its poky little hairs and showy “pot-bellied” flowers.”

Pitman recalls mixed emotions upon the team finding the flower. “We were really excited, but really tentative in our excitement — we thought, ‘Was it really that easy?’” he says. “We knew we needed to check with a specialist.”

From left: Ecuadorian botanists Juan Ernesto Guevara, Xavier Cornejo, and Gonzalo Rivas after a successful day of plant collecting on the Centinela Ridge in coastal Ecuador. Photo by Nigel Pitman

The researchers took photos and collected some fallen flowers, not wanting to harm the plants if they were the only ones remaining on Earth. They sent the photos to taxonomic expert John Clark, who confirmed that, yes, the flowers were the not-so-extinct G. extinctus. Thankfully, the team found many more individuals as they visited other forest fragments, and they collected museum specimens to voucher the discovery and leaves for DNA analysis. The team was also able to validate some unidentified photos posted on the community science app iNaturalist as G. extinctus.

After the field, the work isn’t finished! The team presses and preserves the specimens collected during the day. Photo by Riley Fortier

The plant will keep its name, says Pitman, because biology’s code of nomenclature has very specific rules around renaming an organism, and G. extinctus’s resurrection doesn’t make the cut.

While the flower remains highly endangered, the expedition found plenty of reasons for hope, the researchers say. 

“We walked into Centinela thinking it was going to break our heart, and instead we ended up falling in love,” says Pitman. “Finding G. extinctus was great, but what we’re even more excited about is finding some spectacular forest in a place where scientists had feared everything was gone.”

Botanist Riley Fortier admires the plantations, pastures, and remnants of old cloud forest that cover Centinela Ridge in coastal Ecuador. Photo by Dawson White

The team is now working with Ecuadorian conservationists to protect some of the remaining fragments where G. extinctus and the rest of the spectacular Centinelan flora lives on. 

“Rediscovering this flower shows that it’s not too late to turn around even the worst-case biodiversity scenarios, and it shows that there’s value in conserving even the smallest, most degraded areas,” says White. 

“It’s an important piece of evidence that it’s not too late to be exploring and inventorying plants and animals in the heavily degraded forests of western Ecuador. New species are still being found, and we can still save many things that are on the brink of extinction.”

Research article:

Pitman NCA, White DM, Guevara Andino JE, Couvreur TLP, Fortier RP, Zapata JN, Cornejo X, Clark JL, Feeley KJ, Johnston MK, Lozinguez A, Rivas-Torres G (2022) Rediscovery of Gasteranthus extinctus L.E.Skog & L.P.Kvist (Gesneriaceae) at multiple sites in western Ecuador. PhytoKeys 194: 33–46. https://doi.org/10.3897/phytokeys.194.79638 

Rare, protected orchid thrives in a military base in Corsica

Counting over 155,000 individuals, the population is a world precedent. Globally, this orchid can only be found in the south of France, Italy, and along the east coast of the Adriatic.

In Corsica, away from the eyes of locals and tourists, hides a population of unprecedented proportions of a rare and protected orchid: the neglected Serapias (Serapiasneglecta). In a closed military base in the east of the island, researchers discovered 155,000 individuals of the plant.

Globally, this orchid can only be found in the south of France (including Corsica), Italy, and along the east coast of the Adriatic, but none of its known populations has been as abundant as the one documented in Solenzara.

High density of Serapias neglecta on the air base. Photo by Margaux Julien (Ecotonia)

Margaux Julien, Dr Bertrand Schatz, Simon Contant, and Gérard Filippi, researchers from the Center of Functional Ecology and Evolution (CEFE) and Ecotonia consultancy,came across this population while studying plant diversity in the Solenzara air base. Their research, published in Biodiversity Data Journal, documented impressive plant richness, including 12 other orchid species.

The maintenance of the closed military area turned out to be really favourable to the development of orchids. The flower was abundant around the edges of runways and on lawns near military buildings.

Serapias neglecta. Photo by Margaux Julien (Ecotonia)

“Мilitary bases are important areas for biodiversity because they are closed to the public, are not heavily impacted and these areas have soils that are often poorly fertilised and untreated due to old installations, so they often have high biodiversity,” the researchers say in their study.

The meadows around the airport are regularly mowed for security reasons, which allows orchids to thrive in a low vegetation environment with little competition. In addition, the history of the land with its position on the old Travo river bed favours low vegetation, providing rocky ground just a few centimetres beneath the soil.

“The case of S. neglecta is particularly remarkable, because this species benefits from a national protection status and it is a sub-endemic species with a very localised distribution worldwide,” the research team writes. Moreover, the species is classified as near threatened in the World and European Red Lists of the International Union for Conservation of Nature.

The Ecotonia consultancy also did several inventories on the air base, finding biodiversity of rare richness: 552 species of plants, including 19 with protected status in France. Within only 550 ha, they found 23% of the plant species distributed in Corsica. Among these are some very rare plants, as well as endangered species such as the gratiole (Gratiola officinalis) and Anthemis arvensis subsp. incrassate, a subspecies of the corn chamomile.

Serapias neglecta. Photo by Bertrand Schatz

The Solenzara military base hides rich floristic diversity thanks to its history, management, and the lack of public access. While the Corsican coastline is suffering from urbanisation, this sector is a testament to the local flora, featuring several species with conservation status.

The protection of this richness is crucial. “If logistical developments are carried out on this base, they will have to favour the conservation of this exceptional floristic biodiversity, and, in particular of this particularly abundant orchid. Military bases are a great opportunity for the conservation of species and would benefit from enhancing their natural heritage,” the researchers conclude.

Research article:

Julien M, Schatz B, Contant S, Filippi G (2022) Flora richness of a military area: discovery of a remarkable station of Serapias neglecta in Corsica. Biodiversity Data Journal 10: e76375. https://doi.org/10.3897/BDJ.10.e76375

The tallest begonia species in all Asia found in Tibet, China

Chinese researchers have discovered the tallest Begonia recorded in Asia. The plant belongs to a new species aptly called Begonia giganticaulis.

With over 2050 known species, Begonia is one of the largest plant genera. Since most begonias are small weeds, a begonia taller than a human is a very unusual sight. However, the newly discovered Begonia giganticaulis is one of the few exceptions.

In 2019, Dr. Daike Tian and his colleagues initiated a field survey on wild begonias in Tibet, China. On September 10, 2020, when Dr. Tian saw a huge begonia in full bloom during surveys in the county of Mêdog, he got instantly excited. After checking its flowers, he was confident it represented a new species.

From a small population with a few dozens of individuals, Dr. Tian collected two of the tallest ones to measure them and prepare specimens necessary for further study. One of them was 3.6 meters tall, the thickest part of its ground stem close to 12 cm in diameter. To measure it correctly, he had to ask the driver to stand on top of the vehicle. In order to carry them back to Shanghai and prepare dry specimens, Dr. Tian had to cut each plant into four sections.

A Begonia giganticaulis plant is cut up for easier transportation
A Begonia giganticaulis plant is cut up for easier transportation. Photo by Daike Tian

To date, this plant is the tallest begonia recorded in the whole of Asia.

Begonia giganticaulis, recently described as a new species in the peer-reviewed journal PhytoKeys, grows on slopes under forests along streams at elevation of 450–1400 m. It is fragmentally distributed in southern Tibet, which was one of the reasons that its conservation status was assigned to Endangered according to the IUCN Red List Categories and Criteria.

The research team pose with a specimen of Begonia giganticaulis at the first Chinese begonia show in Shanghai Chenshan Botanical Garden.
The research team pose with a specimen of Begonia giganticaulis at the first Chinese begonia show in Shanghai Chenshan Botanical Garden. Photo by Meiqin Zhu

After being dried at a herbarium and mounted on a large board, the dried specimen was measured at 3.1 m tall and 2.5 m wide. To our knowledge, this is the world’s largest specimen of a Begonia species. In October 2020, the visitors who saw it at the first Chinese begonia show in Shanghai Chenshan Botanical Garden were shocked by its huge size.

Currently, the staff of Chenshan Herbarium is applying for Guinness World Records for this specimen.

Research article:

Tian D-K, Wang W-G, Dong L-N, Xiao Y, Zheng M-M, Ge B-J (2021) A new species (Begonia giganticaulis) of Begoniaceae from southern Xizang (Tibet) of China. PhytoKeys 187: 189-205.https://doi.org/10.3897/phytokeys.187.75854

Standardised expert system method for Navarre grasslands classification based on diagnostic species

Guest blog post by Itziar García-Mijangos

Grasslands represent some of the largest and most diverse biomes of the world, yet they remain undervalued and under-researched. Extending in all continents except Antarctica, they host thousands of habitat specialist endemic species, support agricultural production, people’s livelihoods based on traditional and indigenous lifestyles, and several other ecosystem services such as pollination and water regulation.

Calamintho acini-Seselietum montani in Munarriz (south of Andia Range)

Palaearctic grasslands represent the richest habitats for vascular plants at small spatial scales but are seriously threatened due to land use change. European grasslands experienced two extreme ends of the land-use gradient, intensification of land use on productive lands and abandonment of marginal lands, and both resulted in the loss of grassland biodiversity. It is necessary to understand their biodiversity patterns and how they relate to land use to be able to design conservation and management actions. This understanding requires the harmonization and standardization of grassland classification that leads to a consistent syntaxonomy at the European level and can increase the usefulness of vegetation typologies for conservation and management.

We provide important insights to grasslands, with special focus on dry grasslands, from the western part of Europe (Navarre region, Spain), which constitutes a new step on the pan-European grassland classification. For this purpose, we used 958 relevés distributed across all the region and grassland types, 119 containing also information on bryophytes and lichens. The data used are available in EVA and GrassPlot databases.

The five phytosociological classes most represented in Navarre are distributed according to elevation, climate, soil and topographic variables. The class Lygeo-Stipetea develops in the most Mediterranean areas. On the other hand, the classes Nardetea and Elyno-Seslerietea develop at the highest elevations, linked to the highest annual precipitation and are distributed in the northern areas. Regarding soil, topographic and structural variables the class Nardetea presents the highest soil depth and is also the most acidophilous one. The class Elyno-Seslerietea is characterised by a higher cover of stones and rocks as well as higher soil organic matter content, and, together with Nardetea and Molinio-Arrhenatheretea, is the poorest in soil carbonate content. Conversely, Lygeo-Stipetea stands out by its high soil carbonate content and low soil organic matter. Molinio-Arrhenatheretea stands out for its high cover of the herb layer and cryptogams.

Lygeum spartum communities in Bardenas Reales

We would like to highlight that bryophytes and lichens, contrary to past assumptions, are core elements of these grasslands and particularly the Mediterranean ones of Lygeo-Stipetea, both in terms of biodiversity and of diagnostic species.

We provide, for the first time, an electronic expert system for grasslands in Navarre, based on diagnostic species of each hierarchical phytosociological level from class to association. This expert system can be implemented in the JUICE program and allows the unanimous assignment of any new relevé by means of its species composition to one of the different categories established, which is of enormous value particularly for practitioners. We provide, also for the first time, a detailed databased characterisation and comparison of the syntaxa in terms of their environmental conditions and biodiversity.

Research article:

García-Mijangos I, Berastegi A, Biurrun I, Dembicz I, Janišová M, Kuzemko A, Vynokurov D, Ambarlı D, Etayo J, Filibeck G, Jandt U, Natcheva R, Yildiz O, Dengler J (2021) Grasslands of Navarre (Spain), focusing on the FestucoBrometea: classification, hierarchical expert system and characterisation. Vegetation Classification and Survey 2: 195-231. https://doi.org/10.3897/VCS/2021/69614

Delicious discoveries: Scientists just described a new onion species from the Himalaya

While the onion, garlic, scallion, shallot and chives have been on our plates for centuries, becoming staple foods around the world, their group, the genus Allium, seems to be a long way from running out of surprises. Recently, a group of researchers from India described a new onion species from the western Himalaya region, long known to the locals as “jambu” and “phran”, in the open-access journal PhytoKeys.

The genus Allium contains about 1,100 species worldwide, including many staple foods like onion, garlic, scallion, shallot and chives. Even though this group of vegetables has been making appearances at family dinners for centuries, it turns out that it is a long way from running out of surprises, as a group of researchers from India recently found out.

The flower of Allium negianum

In 2019, Dr. Anjula Pandey, Principal Scientist at ICAR-National Bureau of Plant Genetic Resources in New Delhi, together with scientists, Drs K Madhav Rai, Pavan Kumar Malav and S Rajkumar, was working on the systematic botany of the genus Allium for the Indian region, when the team came across plants of what would soon be confirmed as a new species for science in the open-access journal PhytoKeys.

The plant, called Allium negianum, was discovered in the Indo-Tibetan border area of Malari village, Niti valley of Chamoli district in Uttarakhand. It grows at 3000 to 4800 m above sea level and can be found along open grassy meadows, sandy soils along rivers, and streams forming in snow pasture lands along alpine meadows (locally known as “bugyal” or “bugial”), where the melting snow actually helps carry its seeds to more favourable areas. With a pretty narrow distribution, this newly described speciesis restricted to the region of western Himalaya and hasn’t yet been reported from anywhere else in the world. The scientific name Allium negianum honours the late Dr. Kuldeep Singh Negi, an eminent explorer and Allium collector from India.

Although new to science, this species has long been known under domestic cultivation to local communities. While working on this group, the research team heard of  phran, jambu, sakua, sungdung, and kacho – different local names for seasoning onions. According to locals, the one from Niti valley was particularly good, even deemed the best on the market.

The bulb and underground parts of Allium negianum.

So far only known from the western Himalaya region, Allium negianum might be under pressure from people looking to taste it: the researchers fear that indiscriminate harvest of its leaves and bulbs for seasoning may pose a threat to its wild populations.

Research article:

Pandey A, Rai KM, Malav PK, Rajkumar S (2021) Allium negianum (Amaryllidaceae): a new species under subg. Rhizirideum from Uttarakhand Himalaya, India. PhytoKeys 183: 77-93. https://doi.org/10.3897/phytokeys.183.65433

Rare new orchid species just discovered in the Andes

Three new endemic orchid species were discovered in Ecuador and described in the open-access, peer-reviewed journal PhytoKeys. Lepanthes microprosartima, L. caranqui and L. oro-lojaensis are proof that Ecuador – one of the world’s megadiverse countries – hides much more biodiversity waiting to be explored.

For its size, Ecuador has an impressive biological diversity that harbours a unique set of species and ecosystems, many of them endemic or threatened. Because of this great biodiversity, most studies still focus on recording species richness and very little is known about how these species actually interact. This is why in 2017 Dr Catherine H. Graham from the Swiss Federal Institute for Forest, Snow and Landscape Research WSL, with support from the European Research Council and local NGO Aves y Conservation, initiated an ambitious project in the northwestern Andes of Ecuador to study the ecology of plant-hummingbird interactions along an altitudinal and land-use gradient.

Lepanthes oro-lojaensis. Photo by Diego Francisco Tobar Suàrez

To this end, researchers established 18 transects in areas of well-preserved cloud forest and sites at different altitude and with different levels of disturbance, and visited them monthly to count the flowers that attract hummingbirds and to place time-lapse cameras in flowering plants.

Lepanthes microprosartima. Photo by Diego Francisco Tobar Suàrez

Several new species to science were discovered during the intensive botanical work of identifying the nearly 400 plant species recorded by the surveys and cameras. One of them is a new orchid species called Lepanthes microprosartima.

Found on the western slopes of Pichincha volcano in northern Ecuador, L. microprosartima is endemic to the Yanacocha and Verdecocha reserves, where it grows at 3200 to 3800 m above sea level in evergreen montane forest – remarkably, this species can thrive even under deep shade in the forest.

Over three years of monitoring, only 40 individuals of L. microprosartima were found, which suggests it is a rare species. Because of this, and because it is only found in a small area, researchers preliminarily assessed it as Critically Endangered according to IUCN criteria.

Lepanthes caranqui. Photo by Diego Francisco Tobar Suàrez

Within the same hummingbird monitoring project, another new orchid – Lepanthes caranqui – was discovered in eastern Pichincha. Around the same time, a different research group from the Pontifical Catholic University of Ecuador found the same species in Imbabura. While in Imbabura it was found growing in páramo, with small groups on roadside embankments, in Pichincha it grew in evergreen montane forest, on top of tree trunks or lower branches, in the company of other orchid species. Its name, Lepanthes caranqui, honors the Caranqui culture that historically occupied the areas where this plant grows.

Lepanthes oro-lojaensis. Photo by Diego Francisco Tobar Suàrez

But the wonders of Ecuadorean biodiversity don’t stop there – a research project of Ecuador’s National Institute of Biodiversity found another new species, as small as 3 cm, in the southwest of El Oro. Lepanthes oro-lojaensis was actually discovered on the border between El Oro and Loja provinces, hence its name. It was only found from one locality, where its populations are threatened by cattle ranching, fires, plantations of exotic species, and the collection of shrubs as firewood. This is why researchers believe it should be listed as Critically Endangered according to IUCN criteria.

These additions to the Ecuadorean flora are all described in the open-access, peer-reviewed journal PhytoKeys. They are proof that Ecuador – one of the world’s megadiverse countries – hides much more biodiversity waiting to be explored.

Original source:

Suarez FT, López MF, Gavilanes MJ, Monteros MF, García TS, Graham CH (2021) Three new endemic species of Lepanthes (Orchidaceae, Pleurothallidinae) from the highlands of Ecuador. PhytoKeys 180: 111-132. https://doi.org/10.3897/phytokeys.180.62671