Twitter Botany: Plants in the Roman Colosseum, and in Florence

Illustration from Deakin’s Flora of the Colosseum of Rome, Biodiversity Heritage Library

When Twitter was young, I had a conversation with a librarian who was extolling the virtues of it for research.  I didn’t get it.  From what I had heard, Twitter was where people told their friends about their lives, often the more trivial aspects.  However, she convinced me to try it, with the advice to select a few people and institutions involved with plants and herbaria and follow them; they would lead me to other Twitter feeds.  That was several years ago, and while I know family members and friends have accounts, I don’t follow them.  For me Twitter is about plants.  I usually check it during breakfast and often find at least one interesting item to bookmark and investigate later.  Admittedly, I am not immune to the trivial, and sometimes there will be a retweet of something amusing.  Recently and not surprisingly, a number of these have featured animals (yikes!), and one of my favorites involves two British Labrador retrievers.  But I digress.  What I want to do in this series of posts, as I did in another recent series on miscellanea (1,2,3,4), is to share some of the unrelated items I’ve come across, which reveal Twitter to be a valuable research tool. 

There are two well-known websites that often have botanically flavored posts on relatively unknown aspects of the plant world.  One is Atlas Obscura and the other is the Public Domain Review, which as its name suggests features old publications that are out of copyright; they usually have visual appeal too.  Recently there was a post on Richard Deakin’s 1855, Flora of the Colosseum of Rome.  I had come across this book years ago after a trip to Rome when I fell in love with the city, amazed by how much to its ancient past is still visible.  After four years of Latin, I had an image of the Roman Forum and was thrilled to be able to walk through so much of it, to appreciate its size if not the splendor of its buildings.  What tickled me about Deakin’s book is that someone in the mid-19th century had taken the trouble to thoroughly explore a major ruin and record the 420 plant species he found.  There are illustrations of both the building and some of the plants.  In the copy available through the Biodiversity Heritage Library, the plant illustrations are colored.

While you might not want to know every plant in this famous ruin, you should at least read the illustrated blog post about it.  It’s reveals how nature abhors a vacuum and reinhabits places that humans have come to ignore.  That was the situation with the Colosseum two centuries ago, though by the time Deakin was doing his survey things were beginning to change.  Tourism was growing and efforts were underway to make parts of the structure more accessible and safer for exploration.  This meant removing much of the overgrowth that had accumulated.  Today the process has gone much further, and it’s difficult to envision the floral splendor Deakin experienced, thus making his book that much more valuable.  It documents yet one more ecosystem that has been severely diminished, and an odd one at that.  He found plants there that grew nowhere else in Italy.  A later observer speculated that wild beasts like lions brought from Africa to fight in the Colosseum probably carried seeds with them, so that reminders of these slaughtered animals remained for two millennia, a beautiful example of plant translocation. 

While I am discussing Italy, a blog called Herbarium World should not fail to mention another example of plant endurance in Italy:  the herbarium at the University of Florence.  It is the major focus of a beautifully illustrated book, available as a free download, about the Museum of Natural History of the University of Florence’s botanical collections.  Among them is the herbarium of Andrea Cesalpino, 16th-century student of Luca Ghini, the originator or at least popularizer of dried plant collections in the 1540s (Findlen, 2017).  Cesalpino succeeded Ghini as professor of botany at the University of Pisa and amassed a large herbarium, 15 volumes of which survive today.  He was interested in how to order plants and so arranged his collection according to the classification system he laid out in the first modern work on plant taxonomy (Morton, 1981).  This makes his herbarium a significant historical document and a contribution to a distinguished collection that includes the massive herbarium of the 19th century botanist Philip Webb, who decided to donate his collection to Florence and turn away from his British homeland and Paris where he had worked for years, because he had been treated so well in Italy. 

There are other great collections in the museum including a xylarium and an array of wax plant models.  The city was the center of a vogue in scientific wax modeling in the 18th and 19th centuries, with its anatomical models being the best known and definitely worth seeing at the La Speculo museum.  But plant anatomy, including at the microscopic level, also got its due.  Some pieces have been preserved, as well as models of apples and other fruits that were a way to document the color and shape of different varieties.  Many of these have long ago disappeared as have so much for the Colosseum flora.  We are fortunate that passionate botanists and curators have given us tokens of what has been lost.


Findlen, P. (2017). The death of a naturalist: Knowledge and Community in Late Renaissance Italy. In G. Manning & C. Klestinec (Eds.), Professors, Physicians and Practices in the History of Medicine (pp. 127–167). Springer.

Morton, A. G. (1981). History of Botanical Science. Academic Press.

War and Herbaria: World War II and After

Page from the Jewish herbarium at the Herbarium Frisum

Not surprisingly, rates of natural history collecting go down during wartime.  This was very evident during World War II, yet there were situations where intense surveying was going on.  Richard Howard (1994) has reviewed how botanists contributed to the war effort, particularly by collecting specimens, seeds, and cuttings of Cinchona as a source of the drug quinine for treating malaria, and Hevea as a source of rubber.  Since the Japanese controlled almost all the Asian areas where these essentials were grown, there was a heightened need to find plants that could be cultivated as substitutes, particularly ones that would grow in US ecosystems.  This was hardly a new idea, botanists had been sending back cinchona seed to Europe for centuries, and Kew garden managed to cultivate plants that were then sent out to British colonies, many of which were now inaccessible.

Earlier, in the 1920s, Thomas Edison had gotten into the act of searching for rubber substitutes.  Edison worked with Henry Ford and Harvey Firestone, two men with a definite interest in rubber, in search for promising plants.  They had a number of plant collectors working mainly in the southern US, and they eventually amassed about 17,000 specimens.  Edison even did research at New York Botanical Garden, and curators have found dozens of specimens related to the project, including one with a note from Edison on a specimen of Solidago.  This project didn’t result in any useful rubber substitutes, and most efforts to find one ended when synthetic rubber was developed during World War II.

One unfortunate consequence of war is that herbaria suffer damage.  The most notable example is the destruction of the Berlin-Dahlem collection.  While Humboldt and Bonpland specimens had been moved, most of the remainder of the five-million-item collection was destroyed by bombs in 1944.  The long-time postwar curator of the herbarium, Paul Hiepko, (1987) has written a detailed study of what was lost and what was saved.  Needless to say, the losses included many type specimens as well as historic collections of more than just taxonomic value.  Since then, there has been a worldwide effort to rebuild the collection.

The Natural History Museum, London was also bombed and some specimens damaged either from the impact and fire, or from water used putting out the flames.  Specimens that were in good enough shape to be returned to the collection were stamped with an explanation of their provenance, a useful reminder for future generations of the fragility of specimens.  The Herbarium Frisicum, the largest private herbarium in Europe and housed in Friesland, the Netherlands holds a small Dutch collection that survived the war.  The plants were gathered in the Netherlands between 1940 and 1943 by an unnamed Jewish family.  The fact that the collecting stopped in 1943 is ominous, but the beautiful calligraphy used throughout and the careful preservation of the specimens suggests that the plant world was highly valued and perhaps a source of the comfort to the maker (see image above). 

During WWII, Korean herbaria were  bombed by Japan and collections of native plants destroyed.  Three Korean botanists have written about their investigation of early 20th-century specimens that were lost, but for which they found duplicates in the herbarium at the University of Tokyo (Im, Son, & Im, 2016).  They were able to study this collection and even received specimens from Tokyo for their Korean collection, an example of science going beyond political boundaries.  Though not directly related to herbaria, there is another boundary in Korea that continues to be a political hot spot, the DMZ or demilitarized zone between North and South Korea.  It is quite literally a no-man’s land and consequently, a species-rich territory where cranes and other endangered species flourish. 

There was a similar area where the Iron Curtain separated East and West Germany before reunification, and it now has been turned into a green belt.  The political separation that lasted for almost 45 years led to many disparities between the two areas, especially in how they recovered from WWII, with the differences even extending to the trees.  A comparative study of Hamburg (West Germany) and Dresden (East Germany), each of which had their extensive parks destroyed, found that from early on Hamburg worked to restore green areas in a systematic way and plant large numbers of trees.  Dresden, too, valued trees and boys were sent out right after the war to collect seedlings from the rubble and begin replanting.  But lack of funds and political turmoil prevented a concerted effort, so while Dresden has become much greener, the process was less well-designed. 

There are a number of other conflict-related botanical stories that are at once hopeful and disheartening.  After the civil war in Colombia ended, the fact that the conflict had prevented large forested areas from being logged was considered one of the bright spots for the country’s future.  But now massive deforestation is again plaguing the area.  On another front, Lalage Snow (2018) has written a fascinating book, War Gardens.  She was inspired by the Garden of Babur in war-torn Kabul, Afghanistan.  Babur was the first Mughal emperor and had the garden created around 1528.  He was buried there after his death in 1530, and its restoration has become an international effort.  Snow spoke with the gardener who maintained the property, and the ardor with which he did his job got her interested in other gardening efforts in the country.  She writes of these and also of gardens in Israel and Palestine, the contrasts between and similar passions of the gardeners creating beauty in a hostile environment.  It is a fascinating and sad book with a cover that can only lift the spirit.


Hiepko, P. (1987). The collections of the Botanical Museum Berlin-Dahlem and their history. Englera, 7, 219–252.

Howard, R. A. (1994). The role of botanists during World War II in the Pacific theatre. The Botanical Review, 60(2), 197–257.

Im, H.-T., Son, H.-D., & Im. (2016). Historic plant specimens collected from the Korean Peninsula in the early 20th century (I). Korean Journal of Plant Taxonomy, 46(1), 33–54.

Snow, L. (2018). War Gardens: A Journey through Conflict in Search of Calm. London, UK: Quercus.

War and Herbaria: World War I

Page from Louise Gailleton’s herbarium, National Museum of Natural History, Paris

During World War I, there were a number of soldiers who collected plants, as has been noted for the US Civil War (see last post).  In one case, a set of specimens was found almost one hundred years later, when a granddaughter, who posted in French under the name Darjeeling, wrote of a box she found when her father died.  It held a collection that his father made during the war, marked with the names of the plants and of the battlefields they came from.  There is a significant period when there were no collections, the time he spent as a German prisoner of war, and then he begins again.  The last specimen is of roses from Somme collected in 1962 by his son, with the notation “in memory of September 4, 1916,” during the month-long battle there.  On the herbarium website for the National Museum of Natural History in Paris, there is a page on historic herbaria, including one from a World War I “godmother,” someone who wrote to French troops to help keep up their morale.  Louise Gailleton asked her correspondents to send pressed plants, and she pasted several to a page, each with the species name, the initials of the sender, and the site where it was collected such as Verdun.  On one page, she also pasted a Cross of Valor woven from reeds (see image above).  

The Regius Keeper of the Royal Botanic Garden, Edinburgh, Isaac Bayley Balfour, contributed to the war effort in a significant way by managing a project to produce substantial quantities of sphagnum moss.  Balfour was knowledgeable about medicinal botany and knew that this moss could be a good dressing for wounds after it had been sterilized and dried.  It was preferable to the alternative of cotton wool; the dried moss absorbed 20 times its weight in water and also had antiseptic properties.  In addition, it could be collected in Britain and didn’t have to be imported as cotton was.  Balfour located areas in Scotland where the moss was abundant and organized its collection and processing.  As a result, he was knighted by the king in 1920 for his efforts.  Balfour managed to do this while overseeing the RBGE with a greatly reduced staff.  Half its workforce of 110 enlisted within the first few weeks of the war, with another quarter joining later.  Twenty of these men lost their lives. 

A plant collection that is peripherally associated with WWI is at the Smith College Herbarium and was a created by Frederick W. Grigg.  Among the specimens is a golden club arum, Orontium aquaticum that he found during a visit to Provincetown at the east end of Cape Cod in June, 1918, a time when German boats were sometimes seen on the horizon.  He took this trip from Boston by himself and attracted notice from locals because he had a government map and binoculars that he trained on the wireless station.  This suspicious activity was reported to the train conductor so he could keep an eye on the “suspect” during the trip back to Boston.  The conductor alerted another passenger, a naval officer, who questioned Grigg.  The collector did not take kindly to the interrogation; there was a scuffle, and Grigg ended up handcuffed.  A search of his bag produced maps, charts, a notebook with mysterious notations, and “a botanical outfit,” obviously the stuff of espionage.  When the train arrived in Boston, Grigg asked that the authorities to contact Merritt Fernald, a Harvard botanist, who vouched for Grigg’s character and identified the notations as Latin plant names. 

There are any number of examples of plant collectors’ activities being misinterpreted, especially at times when there can be legitimate reasons for suspicion.  This case ended well.  Grigg must have eventually seen the humor of the situation, since he kept clippings of news items about his brush with the law.  These became part of the herbarium he donated to Smith College.  In the 1970s, a student there, Pamela See, a biology major, investigated the herbarium and drew some of Grigg’s specimens.  These resulted in a booklet published by the college that included the See drawings as well as the story of Grigg’s espionage exploit, an example of the wonderful stories hidden in herbaria.  This one may not have had too much to do with botany, but it’s a great artifact of cultural history that documents the hypervigilance difficult situations can breed, the lure of herbaria as sources of artistic inspiration, and what great results can be achieved when a herbarium curator, in this case John Burk, works with both a student and an art professor, Elliot Offner. 

I’ll end this post by mentioning the plant that is most closely tied to our perceptions of WWI:  the red poppy.  Among the commemorations of the 100th anniversary of WWI’s end were many Twitter posts with images of herbarium specimens of the plant.  It was made famous in a poem by John McCrae with the lines about the rows of soldiers’ graves on former battlefields:  “In Flanders fields the poppies blow/ Between the crosses, row on row. . . .”

War and Herbaria: The US Civil War

Asclepias viridiflora collected by Thomas Meehan in Gettyburg, August 20, 1863; Academy of Natural Sciences of Drexel University

In terms of full disclosure, I should say at the outset of this post on the Civil War that I am a life-long Northerner now living in the South.  I feel very lucky for the opportunity to broaden my viewpoint and to learn about the history of my adopted land.  But I’ve only been here for three years, so I’m not an expert despite my audacity in writing recent posts on several South Carolina botanists (1,2,3,4).  Yet through reading, visits to historic sites, and talks with Southerners, including my daughter-in-law, Laura, who is well-versed in Southern history, I am slowing coming to realize the complexities of that history.  In the last post, I quoted Eran Pichersky (2019) writing that “plants are the foundation of our existence and the ultimate cause of our wars” (p. 12).  This is very true of the Civil War.  Yes, it was about slavery, but it was also about the South’s agriculture; growing rice and cotton were particularly labor-intensive crops, leading Southerners to create an economy based on enslaved laborers. 

Reading Walter Edgar’s (1998) history of South Carolina made me realize how pivotal this state, and particularly Charleston, were to the secession movement.  It was a wealthy city, and its citizens were determined to keep it that way by maintaining the status quo.  Thanks to Bruce Catton’s the Coming Fury (1961) on the buildup to the war, I have a better sense of the machinations on both sides that made the split seem inevitable.  But what has all this to do with herbaria?  I have already written about the work of Francis Peyre Porcher, a Charleston physician, botanist, and plant collector, who produced a book on the plants of the South in 1863 as a reference for those seeking replacements for medicines, foods, and materials no longer available to Southerners cut off from trade.  In addition, Kelby Ouchley (2010) has written an interesting review of plants and animals that were important to troops on both sides; some were useful, some harmful or a nuisance.  Ouchley makes the point that much of the South was still covered by forests at the beginning of the war, and this could both provide cover for troops and also hamper travel.  The animals living there could provide food and also danger.  He presents an interesting perspective on the ecology of war.

By the time the Civil War took place, there was a tradition of botanists traveling with the military on expeditions into the West for surveying, dealing with Mexican and Indian uprisings, and in general learning as much as possible about the relatively unknown parts of the country (McKelvey, 1955).  A number of these botanists were physicians for whom plant knowledge was useful in treating illnesses and injuries, especially when medicines were scarce.  In some cases plant collectors were enlisted to study the flora and geography of untraveled areas and sent their finds to avid botanists in the East, such as John Torrey and Asa Gray who were attempting to document as much of the botanical wealth of the nation as well. 

Traveling alone was dangerous so botanists often sought military protection for their collectors.  Sometimes one person served several roles.  When General Stephen Kearny took Santa Fe during Mexican-American War, his chief engineer and an amateur botanist, William Emory, noted in his journal that the native potato was in full bloom, and he often described battles and plants on the same page.  Botany was a passion that seemingly decreased the stress of conflict (McKelvey, 1955).  The noted California plant collector, John Lemmon, was so distressed by his time in the infamous Confederate prison at Andersonville that he turned to botany for relief of what we would now call post-traumatic stress syndrome. 

Several years ago, the Charleston Museum mounted an exhibit of specimens collected by Charles K. Bell from the former Gettysburg battlefield in the spring of 1894.  He was a student at the Lutheran Seminary near where the first day’s fighting occurred.  Each sheet is marked with the location on the battlefield where Bell collected the plant.  He also included a photo of what the battlefield looked like at the time of the war—bodies, artillery, etc.  There is a note:  “Last thing some mortally wounded Confederate or Union soldier saw was one of these plants,” definitely the thought of a botanically sensitive soul. 

There are hints of botany as diversion in specimens, such as one in the Wisconsin State herbarium collected by a Union soldier, Captain John McMullen, during Sherman’s infamous march through Atlanta.  McMullen sent it to his friend, the botanist Increase Latham, back home in Wisconsin with a note calling it “certainly the most interesting specimen I ever saw” (Senna obtusifolia) and adding that it was “stained with the blood of heroes.”   The Philadelphia nurseryman, Thomas Meehan, did not collect specimens during the battle of Gettysburg, but shortly afterwards.  He visited the site seven weeks later with his brother, who had fought and been wounded there.  It was perhaps a way for his brother to come to terms with his experiences and to share them with someone close to him.  Meehan’s specimen collected that day is at the Academy of Natural Sciences herbarium in Philadelphia, where he was later a curator.  It, like the McMullen specimen, had been sitting there for years unrecognized until recent work on both collections brought these historical treasures to light. 


Catton, B. (1961). The Coming Fury. New York, Doubleday.

de Beer, G. R. (1952). The relations between Fellows of the Royal Society and French men of science when France and Britain were at war. Notes and Records of the Royal Society of London, 9(2), 144–199.

Edgar, W. (1998). South Carolina: A History. Columbia, SC: University of South Carolina Press.

McKelvey, S. D. (1955). Botanical Explorations of the Trans-Mississippi West 1790-1850. Cambridge, MA: Harvard University.

Ouchley, K. (2010). Flora and Fauna of the Civil War: An Environmental Reference Guide. Baton Rouge, LA: Louisiana State University Press.

Pichersky, E. (2019). Plants and Human Conflict. Boca Raton, FL: CRC Press.

War and Herbaria

Hakea ruscifolia collected by Jacques Labillardière in Australia; herbarium of the National Museum of Natural History, Paris

While COVID-19 is the major news topic now, the subject of war seems to come up frequently, at least in terms of comparisons of the present situation with the 1918 flu and its relationship to World War I, or comparing the present death toll to that of the Vietnam War and other conflicts.  So this seems like a good time to look at a question I’ve been collecting information on for some time:  what are the links between herbaria and war?  In Plants and Human Conflict, Eran Pichersky (2019) argues that “plants are the foundation of our existence and the ultimate cause of our wars” (p. 12).  That seems a rather bold statement, but he goes on to investigate conflicts for the control not only of land on which to grow crops, but also of needed water resources.  He notes that three of the four necessities of modern mechanized warfare—grain, steel, oil, and rubber—are plant-derived. 

But where do herbaria come into this picture?  Think of all the specimens collected on expeditions of conquest such as the Dutch taking over the Molucca Islands (now the Maluku Islands) from the Portuguese so they could corner the market on nutmeg and cloves (Nabhan, 2014); 19th-century US government expeditions into Native American lands and attendant conflicts to pave the way for agriculture in the West (McKelvey, 1955); British conquest of India and turning the country into a source for tea, timber, textiles, and other commodities (MacGregor, 2018).  The British botanist William Jackson Hooker even wrote a guide to plant collecting for a manual on science published by the Admiralty (Nesbitt and Carine, 2016).

And then there are herbaria as spoils of war.  An important collection, one that was pivotal to Carl Linnaeus’s work, is the 23-volume herbarium of Danish botanist Joachim Burser (1583-1639).  Containing some Danish, but mostly Central European species, it is arranged according to Caspar Bauhin’s taxonomy and is the oldest collection at the Museum of Evolution Herbarium in Uppsala.  It ended up in a Swedish herbarium and thus accessible to Linnaeus because, after Burser’s death, it was seized as spoils of war when King Charles X of Sweden vanquished Denmark (Stearn, 1957).  In another case, the Swiss botanist Albrecht von Haller’s 60-volume herbarium was bought by the Austrian Emperor and given to the library at Pavia in Italy.  When Napoleon invaded the area, he took the collection back to Paris, where it remains at the herbarium of the National Museum of Natural History (MacGregor, 2007).  Later, when Napoleon led an army into Egypt, he brought a group of natural history collectors with him.  Though his military foray ultimately failed, the same Parisian natural history museum reaped rich collections, including the specimens of Alire Raffeneau Delile who studied plants on the mission and then described them back in Paris (Thinard, 2016). 

In the late 18th and early 19th centuries there were multiple conflicts between the French and British, both major naval powers anxious to gain control of North America and to explore the world as a whole in search of new sources of wealth.  When they were at war, travel and communication between the two countries were often cut off, a problem for scientists who were more interested in the latest research than in politics.  Hans Sloane and his former teacher in Paris, Joseph Pitton de Tournefort did not see any reason to sever connections during hostilities, though it was sometimes difficult to get letters through; they relied on diplomats from neutral nations to pass on messages.  Gavin de Beer’s (1952) article on how such relationships were maintained between France and Britain focuses on the fellows of the Royal Society who would exchange journals with their French friends when regular mail was halted. 

A famous case of magnanimity and fairness in herbarium history involves the botanist Jacques Labillardière who joined a 1791 French naval mission to learn the fate of an earlier expedition that had failed to return from the Pacific, that of Jean-François La Pérouse.  They never did discover what happened to La Pérouse; the evidence of his ship’s wreckage wasn’t found until 1826 on one of the Solomon Islands.  But while stopping in Australia, New Zealand, Tasmania and the East Indies, Labillardière assembled a large collection of over 10,000 specimens, as well as 70 tubs of live plants, and about 600 kinds of seeds.

When the expedition arrived at a Dutch-held port in Java in 1793, the French learned that their king had been executed and that the Netherlands and France were at war.  The officers and naturalists were arrested, but eventually were treated differently depending upon whether they had royalist or republican sympathies (Williams, 2003).  The supporters of the king, including Labillardière, were held, while the republicans were allowed to sail home.   The Dutch seized Labillardière’s collection and sent it on with the French who had been released; their ship was later boarded by the British and the collection confiscated.  

Labillardiére did not return to France until 1796.  By that time, impounded crates of his specimens had arrived in England where the French court was living in exile, welcomed by a sympathetic monarchy.  The collection was handed over to them because Louis XVI had been king at the time the expedition sailed.  The exiles offered to allow Britain’s Queen Charlotte, an amateur botanist with her own herbarium, to select specimens.  However, Labillardière petitioned Joseph Banks, as a fellow botanist and confidante of the British king, to return the specimens in the name of science.  Banks considered science above politics and was attempting to maintain contact with French scientists despite the repeated political duels between the two countries.  Banks returned the collection without even opening it.  This was definitely an act of self-control for a keen collector with his own impressive herbarium (Mulvaney, 2007).  However, as one who had traveled around the world with Captain James Cook and collected thousands of plant specimens, Banks appreciate the toil involved in gathering the plants, preparing specimens, and keeping track of them. 


de Beer, G. R. (1952). The relations between Fellows of the Royal Society and French men of science when France and Britain were at war. Notes and Records of the Royal Society of London, 9(2), 144–199.

MacGregor, A. (2007). Curiosity and Enlightenment: Collectors and Collections from the Sixteenth to the Nineteenth Century. New Haven, CT: Yale University Press.

MacGregor, A. (2018). Company Curiosities: Nature, Culture and the East India Company, 1600-1874. London, UK: Reaktion.

McKelvey, S. D. (1955). Botanical Explorations of the Trans-Mississippi West 1790-1850. Cambridge, MA: Harvard University.

Mulvaney, J. (2007). Labillardière′s Luck. In “The Axe Had Never Sounded” (Vol. 14, pp. 81–86). ANU Press; JSTOR.

Nabhan, G. P. (2014). Cumin, Camels, and Caravans: A Spice Odyssey. Berkeley, CA: University of California Press.

Nesbitt, M., & Cornish, C. (2016). Seeds of industry and empire: Economic botany collections between nature and culture. Journal of Museum, 29, 53–70.

Pichersky, E. (2019). Plants and Human Conflict. Boca Raton, FL: CRC Press.

Stearn, W. T. (1957). Introduction. In Species Plantarum Facsimile (Vol. 1, pp. 1–199). Ray Society.

Thinard, F. (2016). Explorers’ Botanical Notebook. Buffalo, NY: Firefly.

Williams, R. L. (2003). French Botany in the Enlightenment: The Ill-Fated Voyages of La Perouse and his Rescuers. Dordrecht, The Netherlands: Kluwer.

This and That: Art and Science

4 McMahon and Case

“Layered Similarity,” print created by Taryn McMahon and Andrea Case of Kent State University

I cannot end my series of miscellaneous posts (1,2,3) without mentioning one of my favorite topics: the relationship between art and botany.  The example I want to explore here comes from a Kent State University blog post.  This institution has an Environmental Science and Design Research Initiative (ESDRI), an intriguing title for a collaboration among individuals from across the university who are interested in connections between the built and natural worlds.  One participant is Taryn McMahon, an assistant professor of print media and photography.  Concerned with plants and ecology, she was looking for someone with similar interests and was led to Andrea Case, an associate professor of biology doing research on plant reproduction.  I know from experience that individuals who share common interests but are sequestered in different colleges at a university may never find each other.  That’s why an interdisciplinary enterprise like ESDRI is so important:  it makes these links more likely to form.

McMahon was seeking to understand plants more deeply for a print-making project called “Intersecting Methods” curated by Matthew McLoughlin, a Maryland artist.  Every two years he invites a number of printmakers to each submit a piece made in collaboration with a scientist for a portfolio that is exhibited and then each participant receives a set of all the prints.  There is a website where you can see some of the earlier series.  In the course of their collaboration, McMahon and Case discussed their research interests and processes.  They came to appreciate how each approached the ideas they found intriguing.  Case, curator of the Kent State Herbarium, showed McMahon specimens to emphasize that small details in plant structure matter in terms of identification and in how plants function.  McMahon in turn was struck by the fact that her prints were about the same size as herbarium sheets and also, the plants in her prints were arranged very much like specimens as well.

There are also similarities between the working methods of print makers and scientists.  Both start with an initial idea, question, or problem to solve, then experiment to find the right techniques, refine them as they go based on experimentation, do more experiments or make more prints after changing variables, and keep doing this until they come to a final result with which they are satisfied enough to make it public.  Since Case does research on the genus Lobelia, she and McMahon decided to use plants she was growing in making the prints, work which they did together.

What I find most interesting about this collaboration is how the interests of artist and botanist coincided.  Not surprisingly, they both emphasize the importance of observation.  Case mentioned the need to be meticulous in documenting and observing plants.  McMahon noted that a drawing starts with staring at the subject and understanding it; drawing comes only after understanding the form.  One of her most important influences is the 17th-century Dutch artist Maria Sibylla Merian, known for her paintings of insects and plants.  McMahon’s work is very different but it shares Merian’s bold graphic style.  The artist also quoted the philosopher of science Bruno Latour (2004), who argues that matters of fact for scientists can become matters of concern through art.

This is a beautiful and powerful idea.  It says a great deal about both endeavors and speaks of a potent feedback loop between them.  Art makes us look more carefully and feel more deeply, in this case, reaching a different level of understanding of the plant world as a source of color and form.  This experience can make us more willing to look carefully at the plants we encounter.  Looking often leads to questioning:  why are the leaves hairy or the stems sticky or the flowers vividly colored?  Looking more makes the plants in our environment more important to us.  I know this for a fact.  Since I’ve become plant-mad, I see so much more, examine so much more, and am amply rewarded with new knowledge and new questions to answer.

McMahon also sees the scientific viewpoint in dialogue with the art:  asking questions about its meaning and its impact.  Obviously her practice and Case’s are now in conversation with each other, and I hope they will continue their collaboration in the future.  It could lead to a mutual enrichment of their respective projects, and also, perhaps most importantly, enrich their students’ learning experiences, so that the next generation will think of art and science as more closely and inextricably connected than was the case in the 20th century.  The print that the two professors produced together is called “Layered Similarity” (see above).  Bringing my own interpretation to it, as McMahon has invited, I see the dark silhouettes in the foreground as the pressed herbarium specimens and the colored forms bursting behind them as the living plants ready to jump from the page, full of life and in bloom.  Yet they too have a hint of being specimens as well, note the insect damage to the leaves.  These are plants that have been captured in the middle of their lives, warts and all—a disembodied leaf may suggest that its reverse side is being displayed.  There are both literally and figuratively many layers to this print, and if you look at McLaughlin’s site you’ll see prints from other scientist/artist collaborations that all reward careful observation.


Latour, B. (2004). Why Has Critique Run out of Steam? From Matters of Fact to Matters of Concern. Critical Inquiry, 30(2), 225–248.

This and That: Remnants

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Pointed rush, Juncus oxymeris, collected in 1889 by Scottish-American doctor and botanist Anstruther Davidson in the herbarium of the California Botanic Garden.

In a recent post, I wrote about the California Phenology Project aimed at organizing and adding phenology data to online specimens in the Consortium of California Herbaria.  Project activities include a blog, ReCAP, with items that feature interesting specimens, including a piece entitled “What Specimens Reveal about LA History.”  The specimen highlighted was a pointed rush, Juncus oxymeris, collected in 1899 by Anstruther Davidson (1860-1932).  A Scottish physician who had emigrated to California and taught dermatology at the University of Southern California, Davidson was also an amateur botanist and entomologist.  He collected throughout the area and also spent time studying the plants of Arizona.  He contributed many articles to the Bulletin of the Southern California Academy of Sciences and wrote a Catalogue of the Plants of Los Angeles County in 1896.

The Juncus Davidson collected favors a wetland habitat, which at one time was abundant in the Los Angeles basin, with water flowing from the Los Angeles and San Gabriel Rivers into the Pacific.  These waterways have since been tamed and the wetlands drained.  Juncus oxymeris hasn’t been found in this area for a century, though specimens were collected in the 1920s and 1930s in neighboring Orange County.  This example is a powerful reminder of what Los Angeles used to be like and joins many other specimens in linking us to the past.  When I visited the herbarium at the Brooklyn Botanical Garden in 2011, when there was a herbarium at BBG, the curator Kerry Barringer showed me orchids collected on the south shore of Long Island, a few minutes from where I lived.  One was from the area where Aqueduct Racetrack now stands, and another from what is now JFK Airport.  I remember this experience vividly.  It was early in my herbarium obsession and caused a collage of images to flash through my mind:  jets taking off, the smell of jet fuel in the air, and delicate orchids in a wetland—a disturbing juxtaposition.  I had a similar experience years earlier on a visit to the Bell Museum of Natural History in Minneapolis where one of their amazing dioramas portrayed a wetland scene full of birds, and with an explanatory text noting that the area depicted became the site of the Mall of America.

Kathryn Mauz, the author of An Agreeable Landscape: Historical Botany and Plant Biodiversity of a Sonoran Desert Bottomland, 1855-1920, describes another landscape, like most in the world, that has changed considerably over the past century.  The book’s frontispiece is striking (see above).  It is a photo montage of plates included in the book.  The background is a photo of the Cienega Creek Natural Preserve and onto this are placed historic specimens of the plants that used to be found there; it is, in a sense, a visual representation of  the habitat loss scenarios represented by the Juncus and orchid stories.  Here is a place that represents in the present day what is found in herbarium cabinets.

Another example also comes to mind.  Again, once close to my former home on Long Island.  In an area that includes a sports arena, a large mall, and two colleges, there are a few remnant acres of the Hempstead Plains that used to cover 38,000 acres of the island.  Adjacent to the local community college, the site managed to be preserved just as the rest of the area was being developed because it was, and is, home to a number of rare plants.  The preserve isn’t large enough for a visitor to forget adjacent urbanization, but still, it’s a refuge for plants, animals, and humans, one of many havens throughout the country that are small, damaged, and yet steadfast reminders of the landscapes of the past.

Preserving the land is meaningful in a way that a stack of herbarium sheets can never be, yet we need specimens both in documenting what is lost and what has been saved.  Works like Davidson’s Catalogue also contribute to this effort in recording what once flourished in what is now a botanically impoverished area.  One of his articles provides some context for the transformation.  Written in 1907, “Changes in Our Weeds” is a follow-up to an article he had published 14 years earlier on “immigrant” plants in Los Angeles county, an interesting term for a person to use who was himself an immigrant.  Davidson summed up his findings:  “None of those then observed have become extinct:  the relative frequency of the majority have remained unchanged.  Some have increased in numbers, and a few new ones have appeared” (p. 11).  Among the latter was Lactuca serriola, prickly lettuce, a European species.  He found it at one location in 1896, as a fellow botanist did in another area.  “Since that time it has spread so rapidly that it may now be considered the most troublesome weed in this district” (p. 12).  When cows ate it, their milk had a sour taste, but he balanced this observation with one on how chickens and turkeys were fond of it.  There are, of course, endless stories like this about non-natives from around the world, but sometimes it’s good to focus on just one of them, as was done in the blog post that triggered this stream of consciousness post.


Davidson, A. (1905). Changes in our weeds. Bulletin of the Southern California Academy of Sciences, 4, 11–12.

Mauz, K. (2011). An Agreeable Landscape: Historical Botany and Plant Biodiversity of a Sonoran Desert Bottomland, 1855-1920. Fort Worth, TX: BRIT Press.

This and That: Travels of Sophora toromiro

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Toromiro, Sophora toromiro (Phil.) Skottsb, collected 28 June 1800, H. Herrenhus. [possibly Hannover Herrenhausen Royal Gardens], Germany. CC BY-NC-ND 4.0. Te Papa (SP107845)

As with most of the posts in this series of miscellanea (see last post), this story begins with a Tweet, one linked to a blog post and a research article connecting four countries over 250 years.  I’ll try to keep it as simple as possible, by starting in the middle.  In 1877, James Hector, director of the Colonial Museum in New Zealand (now the Museum of New Zealand: Te Papa), asked the British Museum (BM) for a collection of European plant specimens to compare with European plants colonists had brought into the country and were now flourishing, sometimes to the point of being nuisances.  Hector received 28,000 specimens collected by three British amateur botanists: a husband and wife, Silvanus and Bridget Thompson, and Thompson’s student, James Baker.  Most specimens were from cultivated plants gathered in German botanic gardens and the Cels nursery in France between 1764-1864.  Hector never got around to sorting through this gift from the BM; it remained in its original packaging until the 1950s; even today, the only vascular plants to be processed are the orchids.

Recently six specimens of Sophora were found in the collection.  Sophora is a small genus of 17 species in the Fabaceae family and native to the South Pacific.  With eight species, New Zealand is its center of diversity, hence the interest in these sheets that were dated from 1796 to 1822 and were presumably from cultivated plants.  This was surprisingly early for Sophora to be growing in Europe.  Until now, it was thought that the Sophora in Europe were all descended from seeds collected from the 1920-1950s.  There was little plant collecting in the South Pacific until the early 1800s, though Joseph Banks and Daniel Solander had gathered seeds of two Sophora species on Captain James Cook’s first round-the world voyage.  These were planted at Kew by 1772, and there were a few other early cultivations.

The six specimens of interest are in the herbarium of the descendent of the Colonial Museum, the Museum of New Zealand, with the Maori name, Te PapaCarlos Lehnebach, botany curator, and Lara Shepherd, research scientist specializing in DNA sequencing, decided to learn more about the genetics of these six specimens from the 19th-century BM gift.  When Shepherd got the results of her analysis, she was shocked:  one of the specimens, collected in 1800, had genes of Sophora toromiro, a species endemic to Easter Island, Rapa Nui.  It became extinct in the wild in the 20th century, though it is cultivated at several botanic gardens.  At first Shepherd couldn’t believe the results, but when she and Lehnebach looked at the specimen, they found that it did in fact have characteristics of the Rapa Nui plant.  But how did it end up growing in Germany in 1800?

The researchers speculate that seeds may have been collected during Captain Cook’s second round-the-world voyage (1772-1775), when the expedition stopped at Rapa Nui.  The botanists on that trip were Johann Reinhold Forster and his son Georg, with the Linnaean pupil Anders Sparrman as their assistant.   They were the first Europeans to collect specimens on the island, and Sparrman was known to have collected seeds.  He may very well have collected them from this plant, since it grew in thickets and was the only native shrub on the island.  If S. toromiro seeds were planted in the late 1770s, then the shrub would have been established enough to yield cuttings in 1800.  In looking for other Sophora specimens, Lehnebach and Shepherd have found one at the herbarium of the Botanic Garden and Botanical Museum Berlin-Dahlem that could be S. toromiro.  It has no collection date, but it is part of Carl Ludwig Willdenow’s (1765-1812) collection, and a large number of Forster specimens were included in it.  Willdenow had one of those bad habits that frustrates later curators:  he removed the old labels and replaced them with his own, often neglecting to transcribe what’s now considered essential information.

Admittedly, there are suppositions holding this story together, but further work, including analysis of chromosomal DNA from the Willdenow specimen, may make the picture clearer.  In any event, this case study presents a good argument for curating specimens that have been moldering in boxes for decades if not centuries.  This situation is not the result of bad management but of overworked curators without time to deal with the substantial work involved in mounting specimens and providing them with up-to-date identifications.  However, this example suggests the exhilaration that can result from the effort.  Though not every find is a jewel, that’s true of cleaning out any attic.  However, one never knows when a first edition book or a valuable art work might come to light.  My favorite statistic at the moment is that when the herbarium at the National Museum of Natural History in Paris was cleared out prior to renovations about 10 years ago, 830,000 unmounted specimens were found.  Most of them have since been mounted by an outside contractor called in for the massive job (Le Bras, 2017).  But the specimens still need to be curated and filed, a job that amounts to organizing a good-sized herbarium.


Le Bras, G., Pignal, M., Jeanson, M. L., Muller, S., Aupic, C., Carré, B., Flament, G., Gaudeul, M., Gonçalves, C., Invernón, V. R., Jabbour, F., Lerat, E., Lowry, P. P., Offroy, B., Pimparé, E. P., Poncy, O., Rouhan, G., & Haevermans, T. (2017). The French Muséum national d’histoire naturelle vascular plant herbarium collection dataset. Scientific Data, 4(1), 1–16.

This and That: Ehrenberg’s Diatoms

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Images from E. César’s Tweet on the Ehrenberg Collection at the Museum für Naturkunde in Berlin.

Though I have more time to think deeply right now than ever in my life, I’m finding it difficult to do; everything is so different from usual that it’s unsettling.  That’s why I’m not focusing on one topic for a month’s worth of posts as I usually do, but flitting from one topic to another from week to week.  In part this is because of Twitter, my lifeline to the botanical world at the moment.  Thank goodness botanists are interesting people and post interesting ideas.  Most days I find at least one item worth bookmarking and then delving into more deeply.  That’s how I discovered Christian Gottfried Ehrenberg (1795-1876).  I must have come across his name in the past, especially when I was reading about Alexander von Humboldt because Ehrenberg accompanied the explorer on his trip to Siberia in 1829.

A Tweet on Ehrenberg by Edgley César, curator of diatoms at the Natural History Museum, London, included the image above.  It was the photo on the upper right that first caught my eye—obviously old data—and the illustration on the lower left was another lure.  César took the pictures at the Museum für Naturkunde in Berlin where he had spent a week examining specimens of a genus Ehrenberg had described and was amazed by how much work this “founding father” of diatom research had done and how well he drew.  As the thread continued, someone asked about Ehrenberg and César pointed them, and me, to a series of papers published in 1998 dealing with his life, work, and collections.

Ehrenberg was definitely productive throughout his life.  Born near Leipzig, he attended the university there, completing his doctorate on fungi in 1818.  His fungal herbarium is in the Botanic Garden and Botanical Museum Berlin-Dahlem.  From 1820-1825, Ehrenberg participated in an expedition to the Middle East, during which he and his friend Wilhelm Hemprich amassed 114 boxes with 46,000 plant and 34,000 animals specimens as well as seeds, fossils, minerals, and of course, mummies.  Yet the trip was grueling, with three-quarters of team dying, including Hemprich.  Ehrenberg published, Symbolae Physicae, a multivolume work on all aspects of the collection and including 800 plates, many based on his drawings.  He did not describe many of the plants he collected and left the world of higher plants to concentrate on microscopic work, on what were called infusoria, organisms found in decaying matter.  However, he did teach all his children to press plants and create their own herbaria.

A great deal of Ehrenberg’s research was on radiolaria and diatoms.  He considered them all tiny animals and carefully studied their internal structures, which he interpreted as digestive, reproductive, and muscular.  He thought that when better microscopes were developed, these organelles would be seen more clearly.  It is interesting that when diatoms were finally recognized to be more closely related to plants than animals, interest in their internal structures waned, and their taxonomy became based primarily on their elaborate silicate shells that come in a dizzying array of patterns.  The assumption became that there was little difference among these organisms internally; plant cell structures were just not that interesting.  Ancient shells found in diatomaceous earth have long been used in geological exploration, since they are related to oil deposits, but even present-day species are often dried, and just their shells examined.

Ehrenberg made extremely detailed and exquisite illustrations of these organisms and in 1838 published a book with 64 plates on Infusoria in all of their complexity.  He also kept detailed notes on his work, as well as retaining the specimens he’d examined.  Glass slides and coverslips were expensive, so he used small mica discs with a bit of Canadian balsam, a shorthand term for a thick liquid made from the tree’s resin that was a mainstay for 19th-century microscopists because of its optical properties.  Ehrenberg highlighted interesting organisms with small circles, and then with a little more balsam, stuck the discs to his notes.  These have been preserved for almost 200 years, though not without difficulties.

The Ehrenberg Collection at the Museum für Naturkunde consists of 40,000 microscope preparations, 5,000 raw samples, 3000 illustrations, and 800 letters.  It is the combination of different kinds of information that makes it so impressive and valuable, but also daunting.  Most of Ehrenberg’s vascular plant herbarium was at the Berlin-Dahlem botanic garden and was lost when its herbarium was bombed during World War II.  The infusoria, on the other hand, were at the museum and survived but in what would become East Berlin.  The collection was not curated or organized until after German reunification when new resources became available.  It was in light of this that the 1998 article collection was published to showcase Ehrenberg’s work and how the collection could be used, just as César is now using it.  The notes are now beautifully curated (see below), but this required a great deal of work.  The balsam has become brittle, and the mica discs are fragile and difficult to handle.  Over the years some had become unstuck, shifted, and were crushed.  Conservation was necessary because the records contain many type specimens, though as David Mann notes in the last article in the collection, types can present difficulties in terms of hunting them down in a compilation this vast and with all the vagaries it has been through.

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Photo of portion of conserved Ehrenberg Collection at the Museum für Naturkunde in Berlin.

As someone who is fascinated by diatoms, the Ehrenberg Collection is definitely a treasure (see video), along with the diatom collections at the Academy of Natural Sciences herbarium in Philadelphia (see earlier post) and at the Natural History Museum, London.  If you are interested in these beautiful organisms that are classified as algae, you might want to look at Martyn Kelley’s long-running Microscopes and Monsters blog where he deals with microscopic algae and environmental monitoring.

Botanists in South Carolina: Francis Peyre Porcher


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Title page of Francis Peyre Porcher’s Resources of the Southern Fields and Forests from the Biodiversity Heritage Library

Francis Peyre Porcher (1824-1895) was born on his grandfather’s plantation in St. John’s Berkeley outside of Charleston in 1824.  His great-grandfather was Thomas Walter, a Charleston businessman, plantation owner, and botanist who wrote Flora Caroliniana (1788), the first flora of a North American region using Linnaean classification (see earlier post).  Porcher’s parents were also interested in botany.  His father, a Charleston physician, died when he was eight years old.  This left his wife to manage their plantation and raise six children, yet she still found time to satisfy her interest in plants.  Porcher often went botanizing with his mother and uncle.  They were sometimes accompanied by Henry Ravenel, a young man from a neighboring plantation who also had an interest in botany (see last post).  He was ten years older than Porcher, and they remained lifelong friends even after Ravenel moved to Aiken in western South Carolina (Haygood, 1987).

Porcher went to South Carolina College and then to South Carolina Medical College, graduating in 1847.  His thesis, “A Medico Botanical Catalogue of the Plants and Ferns of St. John’s Berkeley, S.C.,” was considered so valuable it was published by the College.  Two years later, this became the basis for his Sketch of the Medical Botany of South Carolina (1849); Henry Ravenel had assisted him on this project.  After graduation, Porcher studied in Europe for over two years at leading medical institutions in France and Italy.  Then he returned to Charleston, where he partnered with Dr. Julian John Chisholm in a practice that included treating the slaves of wealthy plantation owners, many of whom Porcher knew through his family’s plantation (Townsend, 1939).

Since slaves were property, owners wanted to keep them in good health, so it paid them to seek expert care when needed.  In 1855, Porcher and Chisholm founded a hospital for treating enslaved people, since there had never been such a facility in Charleston.  Porcher and Chisholm were being less humanitarians than smart businessmen in establishing a separate medical facility, one that could provide services for difficult cases.  Porcher also visited plantation infirmaries, which were effective for many of the health needs of the enslaved and were usually staffed by enslaved women with expertise in herbal medicine.

When the Civil War began Porcher joined the Confederate medical corps serving first in South Carolina and then at Fort Nelson in Portsmouth, VA where he was stationed until the area was taken by Union troops.  Then the Confederate Surgeon-General, Samuel P. Moore, granted Porcher leave to complete what became Resources of the Southern Fields and Forests in support of the war effort.  Moore had originally asked Porcher to write the book at the beginning of the war, but as the Confederacy’s situation deteriorated, the book was more urgently needed.  Because of his previous publications on South Carolina plants and his medical experience before and during the war, Porcher had already laid the foundations for this text. Besides his own botanico-medical expertise, Porcher had another key advantage in preparing his manuscript:  his life on plantations and his treatment of slaves gave him access to the knowledge of enslaved healers.

Martia Graham Goodson (1987) begins her article on the medical-botanical contributions of African enslaved women to American medicine:  “That the daughters of Africa were a rich source of medical knowledge was not lost on the professional doctors of the Slave South, whose livelihood came from tending sick slaves” (p. 198).  She uses Francis Porcher as an example, noting his sophisticated medical background, including his European studies.  She argues that his education in materia medica began on the plantation where he grew up and depended on his contact with enslaved women working in plantation infirmaries.  For many entries in Resources Porcher mentions how particular species were used by enslaved healers, though no one is referred to by name.  As Goodson notes:  “’Used extensively’ by ‘the negroes’ is a phrase that permeates Porcher’s descriptions of the medical wealth of the plants of his native state.  In fact, nearly one-third of the plants are described as being ‘used extensively on the plantations’ or ‘used by the negroes’ or ‘used in domestic practice’” (p. 200).

Porcher’s 600-page text was published in 1863.  He often went into great detail describing where and when a particular plant was likely to be found, how it should be harvested, and not only what it could be used for, but how it should be prepared for use.  From the number of plants mentioned as valuable in producing soap, curing diarrhea, and treating fever these were obviously critical needs—and very basic ones.  This book was not just for the military, though it was distributed to all Confederate physicians.  Since the South could no longer rely on the Northern states or foreign trade for the medicines and other goods they needed, everyone had to become self-sufficient and utilize local resources as much as possible.

In a sense, Porcher was attempting to make all Southerners practical botanists who could maximize their use of what was available to them, even if they hadn’t hitherto paid much attention to plants in the past.  The book remained popular and was reprinted after the war, when Porcher returned to his medical practice.  Though life in Charleston was difficult as it was throughout the South, he had a needed expertise, a good reputation in his practice, and social connections that still counted for something, with many of these extending well beyond the South because of his service in the American Medical Association.  He resumed teaching at the Medical College, did research on yellow fever, and died in Charleston in 1895.


Goodson, M. G. (1980). African Slave Contributions to Medicine. The Western Journal of Black Studies, 11(4), 198–203.

Townsend, J. F. (1939). Francis Peyre Porcher, M.D. (1824-1895). Annals of Medical History, 1, 177–188.

Note: I want to thank Herrick Brown and Lauren LaFauci for discussions on Francis Porcher that were very helpful to me.  Also, I am grateful for the assistance I received in assessing the Porcher papers at the South Caroliniana Libary at the University of South Carolina, Columbia.