Cave-dwelling plants in SE Asia

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One of the many hundreds, if not thousands of caves located in the limestone karst of SW China. It is within such caves that we are discovering many new species of plants, very often from the nettle family.

Since 2007 I have been working with colleagues at the Chinese Academy of Sciences Guilin Institute of Botany on documenting the unusual cave flora of SW China and Guangxi. My interest stems from the fact that one of the most common groups of plants in these caves are two particular groups of nettles, members of the succulent herbaceous genera Elatostema and Pilea. It is also heavily influenced by the presence of a very knowledgeable and dedicated botanist at the Guilin Institute of Botany, Professor Wei Yi-Gang.

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Examples of some of the strange looking flower clusters in the nettle genus Elatostema, the most common group of nettles to be found growing in caves

More recently I have wanted to see whether it is possible to explain how, and when these plants occupied these ancient caves. Possible explanations are that they evolved in the caves, some of which are 15-25 million years old; alternatively that they represent plants which grew outside of the caves when the climate was different, during the last ice-age for example; lastly that they are relics of plants which grew in the forest understory outside of the caves prior to the arrival of agriculture in the area maybe 1,500 years ago. To try and answer these questions I have, together with a Masters student Alfred Gay, used DNA extracted from the leaves of the plants to look for patterns which may point to one of the three possible explanations above. Click here to see a slide show of the preliminary results.

A carpet of nettles growing in the back of one of the caves that we surveyed in SouthWest China, taken with a tripod!

Another interesting line of research would be how these nettles survive in such low light levels. In some cases 1/50th of 1% daylight! For the moment though I am focussing on documenting their diversity and describing the new species we find but in the long-term I am hoping to find collaborators to explore these other areas of research.


Hidden treasures of the Museum backlog collections

Lichen encrusted boot collected in Ecuador by a Cambridge University Expedition in 1967. The boot was finally accessioned in 2011 and included a new lichen record for Ecuador at the time

All large Museums and herbaria have backlogs of specimens that are waiting to be processed and incorporated into the collections, sometimes for a century or more. Whilst to many institutions, specimen backlogs can seem like an eternal cloud pulling at their consciences, the reality is that they are an inevitable consequence of uneven collecting effort, bequests, absent-minded scientists and the amount of money available to maintain natural history collections. It might be better to think of these collections in limbo as potential treasure troves for those who finally do get the time and resources to process them. Last week I went to meet Natural History Museum (NHM) curator Holger Thüs, herbarium technician John Hunnex and their volunteer team in the backlog processing area of the Botanical Collections.

One of several boxes full of packets collected by a lichenologist called West in the early 1900s. These collections contain many records from all over the UK and are important as they help us see how lichen distributions have changed over the past Century

Thanks to the efforts of Holger and his team at the NHM, over 2,300 boxes of lichen backlog have been processed in the last three years. During their efforts some important and hitherto unknown historical collections have been recovered which include specimens collected by Charles Darwin from Tierra del Fuego, David Nelson collections from Captain Cook’s third voyage and Francis Masson collections from South Africa, as well as many others. Maybe less glamorous though, but of great scientific value however are the big collections of 19th and early 20thC lichens from the UK as these provide an important snap shots that help document the impact of industrialisation on air quality and the landscape as it began and later as it gained momentum. These collections plug gaps in our knowledge thereby making the UK biota one of the most completely known.

Long dispersed between a cupboard in the herbarium and storage areas in the museum towers, this collection of lichens compiled by William Mudd in the middle of the 19thC contains specimens which formed the basis of the first UK lichen flora published in 1861 and material which he received in from colleagues across Europe. It was identified as such by lichen curator Holger Thues and visiting scientist Mark Seaward

Of particular value was the discovery of what is likely William Mudd’s personal lichen collection from the middle of the 18thC and which contains specimens which formed the basis of the first UK lichen flora published in 1861, ‘A manual of British Lichens‘. The 52 book-like fascicles of unbound sheets and hundreds of specimens were  rediscovered dispersed between cupboards in the Cryptogammic Herbarium and in stores at the top of the Museum’s towers where they were thought to represent spare / duplicate material for distribution. The fact that such a treasure was found in the backlog hints at what other amazing collections could be found in the coming years as the work to process it continues.

The William Mudd collections as they are housed now. The volumes are now  stored in a climate-controlled and pest-free space within the Bernard Sunley suite at the Natural History Museum


Training students from the Amazonian University of the Pando

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Students from UAP visiting our partner community, Palacio where Rolman Velarde is explaining and demonstrating the use of Inga agroforest to restore slash-and-burn sites to productivity. Image, Juan Fernando Reyes, Herencia

As well as promoting sustainable alternatives to slash-and-burn our Darwin Initiative Forest Futures project also seeks to raise awareness of the value of natural forest and alternatives to its unsustainable use. With this aim Juan Fernando Reyes and Rolman Velarde from Herencia ran a two-part course for 60 students and lecturers from the Environmental Engineering programme of the Amazonian University of the Pando (UAP). The first part of the course took place at UAP and provided an overview of the ecosystem services that the Amazon provides to the Pando but also at a regional and global level.

The second part of the course took part at one of our partner communities, Palacio. This consisted of demonstrating sustainable agricultural practices: aquaculture and the restoration of soils to productivity using Inga agroforestry. The students were also able to visit our monitoring plot where together with partners from the Museo Noel Kempf we are evaluating the biodiversity and carbon sequestration of the Pando’s forests.

First batch of fish farmed by the Palacio community as part of a Herencia initiated project. These fish are called Pacu and are seven months old and already at commercial weight

‘Win-win-wins in conservation: presentation at UNESCO ‘Botanists of the 21st C’ Conference

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Brosimum alicastrum fruits with the fleshy skin that is consumed by bats and birds, and showing the large seed that drops to the forest floor where it can be harvested. Image by Erika Vohman.

I have been very lucky to present some of the work that Tonya Lander at Oxford University and I have been working on at the UNESCO ‘Botanists of the 21st C’ Conference in Paris. The work builds on a project whose aim was to provide scientific tools for the sustainable harvesting of the underutilized crop and tropical forest tree, Brosimum alicastrum that Tonya and myself undertook in association with the Maya Nut Institute and which was funded by the Darwin Initiative. Tonya and colleagues at Exeter and Oxford University developed a clever way of using investment risk data to help prioritise conservation actions. The basis of this was to use investment risk ratings as a surrogate for the risk of a conservation action failing because of corruption, lack of government infrastructure or capacity

Click here to see a pdf of the slides and notes

September 22, 11 am. Venue: Room IV, UNESCO Headquarters, 7 Place de Fontenoy, Paris, 75007, France

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Rural community dweller rinsing Brosimum alicastrum seeds collected from the forest floor. Image by Erika Vohman.

Coffee interview with the Naked Scientists

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Graihagh Jackson from The Naked Scientists, Lizz Booker from Starbucks and myself in a coffee shop in South Kensington after the interview

On the 13th of September I had the pleasure of working with the Naked Scientists, a media-savvy group of physicians and researchers from Cambridge University who use radio, live lectures, and the Internet to strip science down to its bare essentials, and promote it to the general public. I also had the pleasure of meeting Liz Booker, a coffee taster from Starbucks. The interview was about coffee and the chemistry and the genetics behind its flavour and was in response to scientists having now sequenced the genetic code of one of the the coffee species used to make coffee. I am no expert on coffee but served as botanist for the piece.  After the event I took Liz Booker and Starbucks Press Officer Nicky Gaskell to visit our coffee collections in the Herbarium where we looked at a number of 18thC specimens. The peice was broadcast on BBC Cambridgeshire, BBC 5 Live and Australian ABC, click here to hear the interview and read the transcript

Our first Inga agroforest plots six months on

A member of the Motacusal community standing next to a row of Inga saplings that is well on the way to becoming a functional agroforest plot. Image by Rolman Velarde, Herencia.

We have established Inga agroforest plots on abandoned slash-and-burn sites, degraded pasture and land used for road grading where the topsoil is removed with a bulldozer. After six months seedlings have established on all of these sites but with slower growth and some mortality on the bull-dozed and pasture sites.  We planted out our plot at Motacusal, an abandoned slash-and-burn site at the end of February and since then the seedlings here have done very well, most over 1.5 m in height. At this site we have 1,200 plants growing and they may well ‘capture’ the site a year after planting in six months time. By capture we mean that they dominate the weeds and other competing vegetation and control the site.  Now that the dry season has ended and the seedlings have become saplings we are well on the way to delivering our first agroforest.

Continue reading

A likely new species of Pilea from the Dominican Republic

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A possible new species of Pilea characterized by large tubers which probably enable it to survive in fissures in limestone karst cliffs where it grows. Image Alex Monro.

On my recent trip collecting nettles in the Dominican Republic we came across what is very likely a new species of Pilea, a group of about succulent nettles. I thought it might be useful to outline what happens from collecting / discovering something new to it being published as a new species, from my own botanical perspective of course. In the case of this species, it has a couple of distinctive features which make it stand out from similar looking Pilea species: 1) a well developed above-ground tuber, up to the size of a small potato, and 2) relatively large male flower clusters for the group of species it is in. This gives me two diagnostic characters to check with in existing collections and in the literature. Pilea is a genus of over 700 species found in tropical and subtropical Asia, Madagascar, Africa and the Americas. All but a few species are restricted to one of these areas or a much smaller area and this knowledge enables me to delimit my search area. In this case, the Greater Antilles (Cuba, Jamaica, the Cayman Islands and Hispaniola).

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Close-up of the leaves and flowers. The cluster of red flowers on the left are male and are borne on a relatively long stalk, to the right you can see a cluster of female flowers. This cluster is only a few mm long and contains several flowers.

My second job is to see if the species has already been described. To do this I need to look through the collections of the most appropriate herbaria for this area, starting with the National Herbarium of the Dominican Republic. This can take quite a long time although many collections have been digitised and are available online. I then need to follow this up by reviewing the literature for the region to see if I find any descriptions which match or are close. Once I have done this I should have a list of species that are possible or close matches. These I can then compare in more detail with my possible new species and confirm whether it is new or not. This I will do by looking at the type specimens under a microscope and comparing their key features: leaf and stem shape, the nature of their hairs, the size and shape of the flowers and of course in this case, the presence or not of a tuber. This also provides me with the information I need to write the diagnosis of the new species. Once I am sure that this is a new species I can start writing the description and think of a name. A new species description will include a detailed description of the plant, a line drawing illustrating the diagnostic features and a species conservation assessment which will provide an indication as to how threatened with extinction it is.

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A cross-section through one of the tubers. The tuber likely serves as a water storage device to help the species survive dry periods growing in narrow fissures in rock.

Lectotype of Urtica baccifera L. from Plumier (1760)

lectotype urera baccifera Plumier 1760 tab CCLX Resultpdf-3This beautiful plate from Plumier’s 1760 Plantarum Americanarum was designated as the lectotype for the Linnean name, Urtica baccifera by de Rooij in 1975 ( Fl. Suriname 5: 302).  Whilst very beautiful the plate is not sufficient in its own right to distinguish the species from closely related ones and so I designated an epitype in 2009: Fawcett 7177, collected on 13 Mar 1898; in Jamaica and stored at BM.


Revising the Pilea species of the Dominican Republic

Sorting all the collections of Pilea into species piles based on morphology and existing identifications. I ended up with over 80 piles and 110 names

Pilea is a genus or group of over 700 species in the nettle family (Urticaceae). It is mainly comprised of succulent herbaceous plants that grow in the shade of forest and is especially diverse in the Greater Antilles and on limestone. Currently over 110 species are recorded for the island of Hispaniola which encompasses the Dominican Republic. They are very variable in their shape and form and probably most people (including many botanists) might not think that they were related to nettles. It is a group that I have been working on for over 15 years and I began work on revising their classification for neighbouring Cuba in 2010.  Surveying the species in the herbarium of the National Botanic Garden in Santo Domingo helped me to see how they compared to the species in Cuba.

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Examples of Dominican Republic Pileas: P. depressa, P. microphylla, P. fairchildeana & P. cf christii. These four species demonstratethe great diversity in form of the genus Worldwide and why they are such an interesting group

After a week looking at the collections and sorting them into piles I started to get an idea as to the species present on this amazing island. Of course establishing their correct names involves a whole other body of work but at least I now have an idea as to what there is in the Dominican Republic, what might be conspecific with Cuban species and where there are complexes of closely-related and potentially interbreeding species. Not bad for a week’s work.

Collecting nettle seeds, no easy task!

Collecting Pilea cellulosa fruit on the border with Haiti whilst trying to avoid 300 escaped prisoners. Collecting the fruiting bodies is relatively straight forward but recognising and extracting mature fruit is not.

For a week now I have been accompanying a team from the Jardín Botánico Nacional and Kew’s Millennium Seed Bank on a field trip to collect seed of plants endemic to Hispaniola for banking at the Jardín Botánico and Kew. I have been taking advantage of this trip to collect nettles but also to learn how to harvest and bank their seeds. The Greater Antilles which includes the Dominica Republic  / Hispaniola is a centre for species diversity for nettles and most of the 100 or so species found here are found nowhere else. Given obvious pressure on the island’s forests both in the Dominican Republic as well as in Haiti, banking their seeds could support their reintroduction as a last ditch attempt to prevent their extinction.

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Fruiting Pilea microphylla. For scale the leaves are 3 mm in length. Ripe fuits are brown in colour, immature flowers and fruit pale cream to pale-green.

The seed bank at Kew which banks the seeds of >50,000 species currently has only 14 sp of nettle which for me seemed a little on the low side given that there are about 2,000 species Worldwide. Support from the Bentham Moxon Trust is helping me to increase this figure significantly, both by enabling me to help develop seed-collecting protocols for nettles and so encourage seed banks to collect them, but also because I am learning from them how to collect seeds, something that I can do myself on future fieldwork in collaboration with other seed banks. Continue reading


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