The Plant Press

Researchers find new grass species in Maloti-Drakensberg area in southern Africa

From Plant Press, Vol. 24, No. 1, January 2021.

Adapted from an article written by Leonie Bolleurs, University of the Free State, South Africa.

Festuca drakensbergensis in an Afrolpine grassland field at Tiffindell, Drakensberg Mountains. (photo by Rob Soreng)

In their search to learn more about the impact of humans and climate change on grasses in the Drakensberg Mountain Centre (DMC), one of the most studied mountain systems in the region, a group of scientists found a new grass species, which they named Festuca drakensbergensis Sylvester, Soreng & M.Sylvester [PhytoKeys 162: 50–54, f. 1, 2. 2020] (common name unknown; herein could be designated the ‘Drakensberg Alpine Fescue’). The Maloti-Drakensberg Park World Heritage Site is a transnational property spanning the border between the Kingdom of Lesotho and the Republic of South Africa.

The team who is working on the project includes Vincent R. Clark, Head of the Afromontane Research Unit at the University of the Free State (UFS), Steven P. Sylvester from the Nanjing Forestry University in Nanjing, Jiangsu, China, and Robert J. Soreng from the Department of Botany at the Smithsonian Institution in Washington, DC., along with Mitsy Sylvester and Caroline Mashau (Ph.D. student).

The species, discovered in February and March 2020, was found during extensive fieldwork by the Sylvesters and Soreng and herbarium research across the 40,000 km² Maloti-Drakensberg area. The DMC has a very high endemic plant diversity, says Clark (fieldwork vouchers at NU, PRE, US, and more to be distributed).

“It is the only mountain system in [continental] Africa south of Mt. Kilimanjaro with an alpine component,” Clark adds. The DMC has a montane sub-center (below 2800 m) and an alpine sub-center (2800 to 3482 m).

Fake flowers, real news: a new plant-fungus association in Guyana

From Plant Press, Vol. 24, No. 1, January 2021.

Fungi exploit their environment and interact with plants in a myriad of complex and sometimes devastating ways – from symbiotic associations in lichens, endophytes, and mycorrhizae, to wood decayers and parasites causing crop diseases. One of their most remarkable and rare life-history strategies is floral mimicry, where a parasitic fungus induces flower-like structures. These “false flowers” or pseudoflowers usually are infected leaves that mimic the look, smell, and rewards (a sugary fungal exudate) of real flowers to attract insects which then disperse the fungal spores to other plants for new infections and to effect outcrossing. The best-known systems involve rust fungi and diverse hosts, including Puccinea + Boechera (Brassicaceae), Uromyces + Euphorbia (Euphorbiaceae), and Molinilia + Vaccinium (Ericaceae).

Xyris surinamensis inflorescences comparing similar flowers (left) and fungal pseudoflowers (right). (image by Ken Wurdack)

In a pair of recent papers (Laraba et al., Mycologia 112: 39–51, 2020; Laraba et al., Fungal Genet. Biol. 144: 103466, 2020), Smithsonian Department of Botany scientist Ken Wurdack and mycological collaborators at the U.S. Department of Agriculture and Purdue University describe a novel neotropical plant-fungus association between yellow-eyed grasses (Xyris spp.; Xyridaceae) and a new pseudoflower-producing species of parasitic fungus. This research was begun during BDG-sponsored (Biological Diversity of the Guiana Shield Program) fieldwork by Wurdack, who in 2006 encountered an odd fungus on inflorescences of Xyris surinamensis in the savannas above Kaieteur Falls in the Pakaraima Mountains of western Guyana. Wurdack’s field studies were expanded during plant collecting expeditions in 2010 and 2012 (see The Plant Press 14(1): 1, 9–11, 2011; 16(1): 8–10, 2013) that explored other savannas in this region of the Guiana Shield known for tepuis (table-top mountains) and high biodiversity. The savannas typically form on thin, sandy soils over sandstone rock outcrops in the uplands (300–900 m) between mountain peaks, and are rich in endemic Xyridaceae. The fungus mimics the flowers of Xyris with yellow-orange petaloid fungal tissue that slowly grows to envelope an inflorescence, and apparently fools visiting small bees which otherwise seek to collect pollen. These fungal pseudoflowers had been sparingly noted in the Xyris systematics literature and incidentally collected with plant specimens. Wurdack surveyed Xyris specimens in the U.S. National Herbarium (US as well as MO and NY) and discovered pseudoflowers on 20 historical collections dating back to 1919, which encompassed only four Xyris species (of 250+ worldwide) in the Guiana Shield region of Colombia, Venezuela, and Guyana.

Xyris surinamensis in a savanna along the Kako River in the Pakaraima Mountains of Guyana; fungal pseudoflowers indicated with arrows. (photo by Ken Wurdack)

 

Savanna along the Kako River in the Pakaraima Mountains of Guyana with mixed Xyris species and fungal pseudoflowers on X. surinamensis (indicated with arrows). (photo by Ken Wurdack)

In the research of Laraba et al., a fungus was cultured from the Xyris pseudoflowers that the authors newly describe as Fusarium xyrophilum I. Laraba, K. Wurdack, Aime & O’Donnell, and use molecular phylogenetic analyses to discover its closest relatives are surprisingly from Africa. The fungus was further characterized using modern methods to determine its genome, sexual reproductive mode, and secondary metabolites. Those results paint a detailed picture of the life history of a parasitic fungus that forms unique pseudoflowers made entirely of fungal tissue, can infect all parts of its Xyris host, can manipulate host growth through the production of phytohormones, can produce mycotoxins for defense, and can produce pigments and volatiles that are known to attract insects. Many evolutionary and ecological questions remain unanswered, such as: How did this complex mimicry evolve and how is it maintained despite affecting host fertility? Why is it so host-specific? How does a disease that affects plant fertility coexist with its host? The studies of Laraba et al. are testament to new surprises coming from basic tropical biodiversity research.

ForestGEO welcomes 72nd plot to the network: Ordway Swisher, Florida, USA

From Plant Press, Vol. 23, No. 4, October 2020.

ForestGEO is pleased to introduce its newest research site, the Ordway Swisher Forest Dynamics Plot, a 23.04-ha upland sandhill forest near Melrose, Florida, USA, that undergoes a regimen of prescribed burning every three to four years (including during the establishment of the plot). Field crews began the census in March 2019 and completed it in February 2020, less than one month before the coronavirus pandemic brought fieldwork around the world to a halt. Staff have entered and screened census data, which is now available upon request in the ForestGEO Data Portal. Dan Johnson and Stephanie Bohlman, both of the University of Florida, are the plot’s Principal Investigators.

Photos of the plot, after the jump...

Flora of the Marquesas Islands, a multiphase project

From Plant Press, Vol. 23, No. 4, October 2020.

By Warren Wagner and David Lorence

Among the most isolated archipelagos in the Pacific, the Marquesas Islands, consisting of 12 main islands, are situated in the Polynesian-Micronesian biodiversity hotspot. Some 2,400 miles southeast of the larger Hawaiian Islands (6,423 sq. mi.), the Marquesas Islands are only about 400 sq. mi., around 20% smaller than the island of Kaua`i. Nuku Hiva, the largest island, is just 50 sq. mi. These relatively young islands (0.7 – 5.5 MYA) have some breathtaking and rugged spires and narrow ridges, but none are higher than 4,000 feet. The Marquesan flora displays a remarkably high degree of endemism despite the islands’ small sizes. Nevertheless, human colonization and the introduction of non-native invasive animals and plants over the years have severely impacted the low- to mid-elevation vegetation of the Marquesas. Scattered like green jewels across a remote swath of the South Pacific and seemingly far from the trappings of modern society, the Marquesas have long been a source of fascination for outsiders.

Plakothira perlmanii (Loasaceae), one of three species of one of two genera endemic to the Marquesas Islands. (photo by Jean-Yves Meyer)

As a result, these islands have attracted a variety of individuals looking to connect with nature or a Polynesian culture free from Western influence. Notably, French painter Paul Gauguin and Belgian singer Jacques Brel both spent the last years of their lives in the Marquesas and were both buried in the cemetery at Atuona, Hiva Oa. The islands have also attracted famous writers and explorers such as Robert Louis Stevenson, Herman Melville, Jack London, and Norwegian ethnographer Thor Heyerdahl who wrote a book called Fatu Hiva during his year-long sojourn on the island where he and his young bride attempted (unsuccessfully) to live off the land. Today the Marquesas are reliably connected to the outside world by satellite dishes and mobile phones. There are airports on four of the main islands, although boat travel is required to reach the others. Nevertheless, many Marquesans still maintain strong connections to the sea and land, subsisting by fishing, hunting, and growing much of their food in agroforests and plantations, as well as selling copra and, more recently, noni (Morinda citrifolia L.) which has become popular as a nutraceutical.

The two of us became acquainted while doctoral students at Washington University in St. Louis, Missouri. In 1987–1988 both of us assumed new research positions: Lorence at the National (then Pacific) Tropical Botanical Garden (NTBG) and Wagner at the Smithsonian Institution (formerly at the Bernice P. Bishop Museum). Since the Smithsonian Department of Botany and NTBG had a significant history of working on Pacific islands, it seemed like a great opportunity to collaborate and develop interactions between the two institutions. One logical project was a flora of the Marquesas Islands because of the years of previous work by Smithsonian researchers F. Raymond Fosberg and Marie-Hélène Sachet in the Marquesas and other Pacific islands, and the focus on Pacific botany by NTBG. The Marquesas flora project was initiated informally on Kaua`i in 1988 over drinks during a meeting with Peter H. Raven, who received the Robert Allerton Award that year. So, with a toast and handshakes the NTBG-SI Marquesas Flora project was born. It was conducted under an agreement with French Polynesia to be a collaborative project between the National Tropical Botanical Garden, the Smithsonian Institution, and the Délégation à la Recherche de la Polynésie Française intended to provide a foundational knowledge of the flora as a vital component towards preserving the biodiversity of the Marquesas Islands.

 
Left: Warren Wagner and David Lorence aboard the sailing vessel Aeolus contracted for interisland transport, owned and captained by Eward H. Carus Jr., during their first collecting trip to the Marquesas Islands in 1988. (photo by E. Carus)
Right: Warren Wagner (left) and other members of the field team (Steve Perlman and Jacques Florence) standing next to the only vehicle they found to rent on Nuku Hiva, during the first collecting trip to the Marquesas Islands in 1988. (photo by D. Lorence)

ForestGEO network adapts in response to COVID-induced changes

From Plant Press, Vol. 23, No. 3, July 2020.

On March 11, the World Health Organization declared the COVID-19 (coronavirus) outbreak a global pandemic. Since then, daily life around the world has drastically changed, and physical distancing, face masks, and a surge in teleworking have become a way of life for many. Fieldwork at Forest Global Earth Observatory (ForestGEO) sites around the world has been severely impacted, with many unique long-term monitoring projects on hold. Decades-long studies of flowering and fruiting patterns of trees, foraging behavior of primates, dynamics of insect populations, and the 40-year census of the Barro Colorado Island (BCI) plot are now stopped. These interruptions are going to have lasting effects on our ability to understand how the world's forests are responding as climate changes. Alongside the disappointment and uncertainty that COVID-19 has introduced, a spirit of flexibility, a willingness to adapt and rise to the occasion wherever possible, has also emerged. Below, ForestGEO staff share how members within the ForestGEO network have found opportunities amid the disruption.

Cliffson Idigel and Joseph Kua, field crew members at the Wanang 50-ha plot (photo from Wanang’s first census). (photo by George Weiblen)

Although physical distancing precludes field crews from embarking upon Wanang’s third census, colleagues at ForestGEO's partner institution, the New Guinea Binatang Research Center, have been able to continue with research throughout the coronavirus pandemic. Vojtech Novotny, a principal investigator (PI) of the Wanang plot in Papua New Guinea, frames travel restrictions and their fallout on scientific research “as a test on the rhetoric of ‘capacity building’ within tropical countries,” noting that “if a sudden interruption of international travel causes tropical research to stop, then it is a sign that the capacity building has not been really robust.”

That time when we all stayed home: The critical need for herbaria and continued plant collecting

From Plant Press, Vol. 23, No. 3, July 2020.

By Julia Beros

Herbaria are not static institutions. They are not dust boxes growing stale or overgrown libraries of dead plants. Yet there is a stigma that knowledge of local flora has reached its capacity, taxonomy is “old school”, and resources should not be allocated to grow herbarium collections. “A collection” implies perhaps a finite assemblage of representatives of a flora, a catalogue of greatest hits, and a singularly definitive portrait of a biological moment in time. A biological collection though is more principally representative of change. Collections serve as a record of biodiversity with supreme detail that informs all other aspects of plant research: systematics and floristics, evolution and ecology, conservation and land management, and education. Though beyond this, collections record the activity of scientists and research institutions, and places this scientific effort into an historical context. It is likely that the current coronavirus pandemic will leave a great void in the biological records of herbaria as it alters the capability, resources, and focus of plant collecting as the pandemic continues to limit and alter the ways in which we may safely interact with our world. Currently, a piece of our landscape’s history is at risk of being erased, or more so never being recorded.

Through the collaborative work and careful planning of NMNH and the Department of Botany, botany contractors Victor Shields and Julia Beros have returned to the museum to turn the lights back on in the conveyor room. Picking up right where they left off, they continue to image the Poaceae. (photo by V. Shields)

It has been noted (for some time now) that plant collecting was already on the decline before the COVID-19 pandemic stalled many research trips. According to Prather et al. 2004 (Syst. Bot. 29:15-28), the general trend for plant collecting has been on decline since the 1960s (taken from a diversely sampled 71 herbaria). Discussed by Daru et al. 2017 (New Phytol. 217: 939-955), (and referencing many other discussions of the great decline in plant collecting) the ramifications of this trend are amplified by the widespread biases in herbarium collections. These biases include the influence of “mega-collectors” whose preferences shaped the content of collections beyond their own time at an institution. Other biases are temporal, geographic, and spatial, all limiting and skewing collections representation.

Presently the general focus for many institutions is largely in the Neotropics, as it is still understudied in comparison with many temperate floras, often shifting resources away from local floristic studies. With strong efforts being made to study and research the tropical flora, particularly in the Amazon, there is also a growing concern for repatriating and protecting the biological property of countries in these intensely studied regions (to mitigate the effects of scientific and economic exploitation as has been a recurring theme in history). However, there is continual evidence that temperate floras are not “complete” as new species are still being described, ecologies change rapidly with urban growth, destruction, and climate change (often altering plant distributions and population sizes), and species extinctions are not being fully documented.

There is another urgent danger: outlined in a letter to Congress from the American Alliance of Museums, it is estimated that nearly a third of museums are in jeopardy of permanently closing because of the conditions of the pandemic, and this includes herbaria. In addition, Funk and Morin 2000 (SIDA 18:35-52) note that herbaria in the southeastern U.S. are at a high risk of closing, making the floristic study of those regions an urgent endeavor. Despite facing the continued everyday challenges of low resources and staffing, and the urgent concern for the future of small herbaria, herbarium collections still provide incredible raw data for researchers and inform new scientific findings regularly. 

2020 has shaped an incredibly unique scenario marked by viral and societal factors whose clash are catalyzing great change. Similar periods in history show a pause in collecting at the U.S. National Herbarium. In 1918 during the flu pandemic, accessioned collections dropped nearly in half from the previous year. Despite the challenges during the 1918 pandemic, local teen botanical enthusiast, Helen Barron, collected, pressed, and mounted plants, creating a personal herbarium that reflects the flora of Washington D.C. during that time. Leaving behind a catalogue of books filled with tenderly pressed and methodically labeled specimens, Barron’s recreational botany has offered the unique perspective of plant collecting in a pandemic.

Helen Barron’s herbarium book, Spring Flowers 1917-1918. (photo by Sue Lutz)

Staff activities

From Plant Press, Vol. 23, No. 2, April 2020.

From February 1 to March 17, Robert Soreng traveled to South Africa and Lesotho to collect grasses and study high elevation grasslands in the Mulati-Drakensberg Mountains with Steven Sylvester (Nanjing Forestry University, China), Mitsy Sylvester, and Vincent Ralph Clark (University of the Free State, South Africa). The team made over 350 collections of grasses from 41 genera. Sets were left for the South African National Biodiversity Institute (PRE) and the University of KwaZulu-Natal’s Bews Herbarium (NU); the U.S. National Herbarium (US) set is expected to be shipped to Plant Protection and Quarantine (PPQ). They also conducted vegetation surveys of over 220 plots. The team visited PRE herbarium in mid-March. Soreng flew home early to the United States from South Africa the day before the airports closed down due to travel bans related to the COVID-19 virus. The Sylvester family is stuck in South Africa indefinitely.

Drakensberg Mountains, South Africa, with a view of Sentinel Peak (right) and Devil’s Toothpick, (narrow pinnacle in center). A botanical team made over 350 collections of grasses from this area, a place that was used in filming the fictional land of Wakanda in the 2018 movie Black Panther.

Searching for holy wood in the dry forests of Colombia

From Plant Press, Vol. 23, No. 1, January 2020.

By Betsy Collins

I recently spent two unforgettable weeks collecting in the tropical dry forests of Barranquilla, Santa Marta, and the Cauca River valley in Colombia for my doctoral research on the phylogeography of the dry forest specialist tree, Bursera graveolens (palo santo, holy wood). Other than its deliciously scented essential oils and funky fruit, what makes palo santo in particular so interesting to study?

Left: Essential oil dripping from a cut in the bark of a Bursera graveolens tree in Piura, Peru. Right: Palo santo fruit are dehiscent drupes. Fruits are green when unripe, and then turn red and the capsule dehisces, exposing a red pseudaril covering the black pyrene. (photo by Betsy Collins)

Palo santo as currently described has a wide range, from Mexico, Central America (except Belize and Panama), Colombia, Venezuela, Ecuador (including the Galapagos), and Peru, although I hypothesize that it consists of multiple, distinct species. This widespread distribution is unique amongst dry forest specialist trees, which makes palo santo an ideal candidate for studying the evolutionary processes that formed the tropical dry forest biome, and whether these processes differ between Mesoamerican and South American dry forest.

One of my goals was to sample (almost) all the major tropical dry forest patches that palo santo occurs in, which is no small logistical feat!

New publication highlights the Guiana Shield plant collections

From Plant Press, Vol. 22, No. 3, July 2019.

Report from Guyana, June 1994: Having just flown into Kaieteur National Park, Carol Kelloff, Paula DePriest, and Mike Tamessar (University of Guyana) realize that Eric Christenson, who had flown in with them, is missing. Christenson is found at the airstrip, with camera and gear unpacked, focused on a Vanilla bicolor Lindl. vine in bud. “Christenson had only seen an illustration of this flower and was questioning whether the subtle colors of blue and pink that were “painted” on the original drawing were the true colors. He […] was willing to camp out under the vine not to miss the opportunity. […] The next morning the flowers opened, and Christenson was very pleased to see that the artist’s rendering of the colors was correct.”

Eric Christenson on the trail from Kaieteur Falls to Tuiket, June 1994. (photo by Carol L. Kelloff)

Carol Kelloff, Vicki Funk, and Sara Alexander have published “Smithsonian Plant Collections, Guiana Shield: 1985–2014, Biological Diversity of the Guiana Shield Collectors” (2019, Smithsonian Institution, Smithsonian Contributions to Botany), which covers the collections of 36 collectors. This volume is intended as a reference for herbaria holding collections made during collection trips sponsored by the Biological Diversity of the Guiana Shield Program (BDG), and as an aid to botanists and taxonomists interested in the region. Part I contains expedition narratives and maps of teams’ routes; part II lists collection localities by collector, with collection number ranges, habitat descriptions, geographic coordinates, and assisting collectors; part III lists collections in numerical order with identifications; and part IV lists collections ordered by determined taxonomic name; followed by four plates of color photos. It also includes a dedication to Tom Hollowell, data manager of the BDG from 1996 to 2005. The publication is available as a free pdf download at https://opensi.si.edu/index.php/smithsonian/catalog/book/210.

30 Years of the Biological Diversity of the Guiana Shield Program

From Plant Press, Vol. 21, No. 2, April 2018.

Kaieteur Falls, Guyana. (photo by Carol L. Kelloff)

The Biological Diversity of the Guiana Shield Program (BDG) recently celebrated its 30th anniversary. This dynamic program seeks to document, study, and preserve the biological diversity of the Guiana Shield. The Shield is a natural area occupying the northeast corner of South America and has a rich and poorly explored biodiversity. Understanding diversity in the area is complicated by the fact that it encompasses six political units (Guyana, Suriname, French Guiana, and parts of Colombia, Venezuela, and Brazil) and five languages. The Shield includes a wide variety of habitats including the unique "Lost World" tepuis and towering greenheart forests as well as savannas, lowland and montane forests, and coastal mangrove areas each of which has a complex interaction of plants and animals.

BDG has worked to explore this rich diversity and to make the information available and useful to the public and a variety of agencies. Although based in the Department of Botany at the National Museum of Natural History, the program has interacted with scientists in almost all of the Natural History biodiversity departments as well as the National Zoo, Smithsonian Tropical Research Institute, and the Smithsonian Conservation Biology Institute.

To accomplish its goals, BDG has a worldwide network of collaborators. In fact, the program has worked with over 850 people in research, education, training, and outreach. These efforts have resulted in tens of thousands of new collections that have been used to address a variety of questions from the basic “What is it?” and “Where does it live/grow?” to synthetic ones, such as “What is it related to?”, “What are the levels of endemism?”, “Are there adaptive radiations?”, "Where are the highest areas of species richness and endemism?", "Where should future expeditions go?”, and others.