The Algal World: So Much More


Fucus evanescens specimen from the US National Herbarium, Smithsonian Institution

I have devoted the last two posts to diatoms and before that to the 19th-century interest in seaweeds in general. But there are many other aspects of algae deserving attention, for example, the onslaught of forces causing damage to ocean ecosystems and thus to algae including a documented decrease in phytoplankton over the last century. At the same time, excessive algal blooms have become more common such as several on Lake Erie, including one that covered an area the size of New York City. Also, a number of macroalgae collected in the 19th century have not been found again in the 20th. In order to have reference specimens readily available to monitor aquatic life, the National Science Foundation has funded a major project called the Macroalgal Herbarium Consortium. Forty-nine US institutions have digitized their macroalgae collections, and all these specimens are now available through one website, the Macroalgal Herbarium Portal. Kathy Ann Miller, a curator of algae at the herbarium of the University of California, Berkeley explains the importance of the collection she manages in a short video. She makes the point that this is a living collection in the sense that she and her students frequently go on collecting trips along the California coast, sometimes finding as many as 400 species in an area. At the moment the Berkeley collection includes more than half of all known macroalgae species.

The Steere Herbarium at New York Botanical Garden also has an impressive collection, and now thanks to the Macroalgal Portal we are all able to access these specimens on the web. This doesn’t do us any good if we don’t know much about algae. But the web can help with this problem. The Smithsonian, also with a significant macroalgal collection, hosts a website on seaweed research with links to other sites, many dealing with species in other parts of the world. If you want to look at some beautiful specimens, and get basic information on them, the natural history museum in Wales also has a good site. The Natural History Museum’s AlgaeVision portal combines basic information on algae with links to its online collection. So once you’ve read about algae, you can investigate many of the different types, and if you just want to feast your eyes on some beautiful specimens you can’t do better than to go to Seaweed Collections Online. I hope that by this time, I have whetted your appetite for these water-loving plants, of all sizes, from the unicellular to giant kelp. Next time you are near a body of water, particularly at low tide at a beach, seek out some specimens. They may not look very attractive and are likely to be slimy to the touch, but persist and maybe stick a few in a plastic bag. When you get home, put them in water, slip a piece of heavy white paper under one of them, and slowly lift it out of the water, keeping it horizontal. See what you’ve got. Your specimen might look surprisingly good. If so, cover it with wax paper, place it between two pieces of board or cardboard and let it dry. Needless to say, if you need help with all this, it’s easy to find on the web. Perhaps you will be in the vanguard of a new era of interest in these organisms.

The Algal World: More Diatoms


Round Loch of Glenhead, watercolor by Martyn Kelly.

I have a bit more to add on diatoms; there just wasn’t enough space in my last post. I have already mentioned diatomaceous earth, composed of the remains of ancient diatoms. It is used for polishing because of the abrasiveness of the glassy shells made primarily of silica. The tiny, hollow shells have a great deal of surface area making them effective filtering agents as well. The earth can also be employed as an insecticide because the abrasiveness damages the waxy covering on many insects. Perhaps the greatest impact of diatoms on our life style today is that their internal remains are a major component of fuel oil, which was created from deposits of many kinds of plant material including the aquatic variety. In fact, the diatom contribution was so significant that some researchers today are considering diatoms as a form of future biofuel, in part because, among phytoplankton, a higher proportion of their fatty acids are monounsaturated making them a better starting material for biofuel.

One of the best and most engaging ways to learn more about diatoms and about how they are used to evaluate aquatic environments is to read the posts on Martyn Kelly’s Of Microscopes and Monsters blog. Kelly heads a consultancy firm in Britain that specializes in studying freshwater ecosystems, and diatoms are key to this research. He is an expert in the field but he writes very appealingly for nonspecialists. He has even produced a book on the subject that is available for a free download from his website. He describes what a diatom population tells about water quality, and how this changes with season and location. Kelly has been doing this work long enough that he can also discuss how things have changed—for better or worse—over time. He travels widely on business so there are posts on his experiences studying diatoms and other phytoplankton in many locations; there have been recent posts from India.

I should note that Kelly can definitely be opinionated in his posts, which is not a bad thing. He provides a sense of the political and economic issues surrounding diatoms—they are not only about beauty. As an independent consultant, he is a little freer to speak his mind, and as a Briton facing exit from the European Union, he has some interesting things to say that what this might or might not mean for environmental regulations in the United Kingdom. Kelly also looks at the local level, at such issues as how a new housing development is likely to affect nearby lakes and streams and what can be done to mitigate the changes. So there are many reasons why his writing is worth checking out.

What makes Kelly’s website particularly interesting is that he is also an artist, who returned to school to take up art seriously. I don’t think it’s a coincidence that he chose to focus on diatoms, because as I said in my first post on algae, they are particularly appealing aesthetically, and this is especially true of diatoms. In his effort to communicate about aquatic environments, Kelly sometimes includes his watercolors in posts. They are beautiful and portray the atmosphere of an underwater world. He includes not only diatoms but other planktonic organisms that would be associated with them in a particular body of water. Some of these works are also included in his book. I think it’s particularly powerful when a biologist is also an artist, because they bring knowledge and years of observation to their art. Kelly presents diatoms in a very different way than does Haeckel, whose portrayals are greatly enlarged, with all the structural details laid out for the viewer as static, structural monuments. Kelly’s diatoms, on the other hand, do not have as many details, but they are shown as immersed in their environment rather than separate from it, and there is a sense of movement. I see these two approaches as complementary and definitely worth studying. We are very fortunate that both are freely available on the web.

Kelly has written on other algal art available on the web, including Andrew McKeown’s cast-iron sculptures of diatoms at East Shore Village on the Durham coast in Britain. They are in a park with a view of the ocean and are tangible expressions of these tiny creatures, something a child could play on and experience in a very different way than they could the real thing. At the other end of the size spectrum, there is a genre, if you can call it that, of arranging diatoms into patterns on microscope slides, a form of tiny art. This has been going on since the 19th century, but still persists today. One major exponent was Carl Strüwe, a German photographer with an expertise in photomicroscopy. He created stunning images, many of diatoms artfully arranged; there was an exhibit of his work held last year called Microcosmos. He was not alone; there was a small group of devotees of this art in the Victorian era, mirroring the broad interest in both microscopy and aquatic organisms. Nor is the practice dead. Klaus Kemp is a British microscopist who creates complex symmetrical arrangements of diatoms. There is a fascinating video of his work and how he creates them. Some people might consider this scientific kitsch, but I see is as one more way to lure nonscientists into the world of science through wonder. They may be initially attracted by the symmetry, become more interested when they learn that the pattern is created under a microscope, and are then hooked by the intricacy and beauty of each tiny element: how can creatures so small be so complex?

The Algal World: Diatoms


Diatom plate from Haeckel’s Art Forms in Nature

I was first attracted to diatoms by their exquisite beauty. When I studied aesthetics many years ago, beauty was often defined in terms of categories such as symmetry and form, and diatoms are definitely exemplars of both. They are one-celled algae, each encased in a glassy silica shell that varies with species. These structures can be elongated, triangular, circular, square, or more elaborately shaped. There is no better introduction to them than the diatom plate [shown above] from Ernst Haeckel’s Art Forms in Nature (1904). There are also great microscope photographs of diatoms on the web, at sites such as Micropolitan University. If you want more than just images, the Natural History Museum, London has Diatoms Online and the Academy of Natural Sciences (ANS) in Philadelphia (now part of Drexel University) has a Diatom Herbarium, both a real and a virtual space.

I visited the diatom collection at ANS two years ago and was drawn into a very different kind of herbarium world. Yes, there are metal cabinets, but they are filled with boxes of microscope slides, not sheets of white paper in folders. This collection was begun in the mid-19th century by members of the ANS who were interested in microscopy. At the time, this was, like seaweed, a hobby for many people who had the money to have leisure time and to buy a microscope. Some were physicians who had some familiarity with microscopes through their profession; others included bankers and industrialists who simply became fascinated with what couldn’t be seen with the naked eye. Like seaweed collecting, this was an area of interest in Britain, and also on the Continent, and had begun in the 17th century (Stafford, 1996). By the mid-19th century, microscope optics had improved and the instruments were easier to use. Many of the ANS microscopists were interested in fossilized diatoms found in diatomaceous earth, which could be found in areas around Philadelphia. This fine, sandy material is used in polishing among other things and represents the remains of organisms that lived in great numbers millions of years ago. Since diatoms are responsible for 20-25% of the earth’s carbon fixation, it’s difficult to overestimate their abundance, both now and in the past.

Eventually, the microscopists’ diatom collections morphed into the ANS Diatom Herbarium, which now houses the second largest such assemblage in the world. Along with slides, there are small glass bottles filled with diatomaceous earth collected in various locations. These are particularly difficult to catalog because each sample contains many species. In some cases, small portions of these sands have been separated out with individual species mounted on slides, but as Maria Popanova, the curator of the collection, notes the bottle that was the source of a particular mount wasn’t always recorded on the slide. There are ways of backtracking using dates and collection sites, but it’s time-consuming work and slows down digitization of the collection. However, 63,000 specimens are now available online. Also at ANS are rare 19th-century exsiccatae that contain many type specimens. These are store in book-like boxes with specimens either mounted on slides or in tiny envelopes. A counterpoint to these historically important items are posters on the walls of scanning electron microscope images of diatoms revealing an even more elaborate detail than that provided by a light microscope. The images are more expensive to produce so not every diatom receives this attention, but these images highlight the complexity of these minute structures.

I could easily dwell on the aesthetic aspects of these creatures, but I want to also stress their scientific significance. There are good reasons why the herbaria such as the ANS and NHS, among many others, maintain diatom collections. The cells can tell us a great deal about aquatic life of the past, the present, and the future. Diatoms serve as useful markers of aquatic ecosystem health. Their shells remain after death, providing stable evidence of water quality. A water sample’s use in monitoring usually deteriorates with time as organisms die, but this is a lesser problem with diatoms. Also, they are ubiquitous, found all over the world in both fresh and salt water. The species present at a site depend upon the presence or absence of pollution, among other factors.

Part of the research done at ANS involves water monitoring studies and having a rich diatom collection, including many type specimens, as reference adds weight to the findings. This work has a long history at the ANS, and the person most responsible for building its stature was Ruth Patrick (1907-2013). She had a doctorate based on diatom research from the University of Virginia and wanted to volunteer at the ANS in the 1930s. She was kept out for several years because they didn’t accept women. She finally became a volunteer in 1935, serving first as a virtual servant to the Microscopy Section, setting out specimens for their meetings among other duties. She eventually became the first woman member of the ANS. In the late 1940s, after she became a paid employee, Patrick founded the ANS Limnology Department. Through her work, the ANS developed a focus on freshwater diatoms; before that it had collected mostly fossils and saltwater species. She directed studies on rivers and streams, especially in terms of using diatoms to gauge water quality, and her influence lives on in the ANS’s Patrick Center for Environmental Research.


Haeckel, E. (1904). Art Forms in Nature (Vol. 1974 ed.). New York: Dover.

Stafford, B. M. (1996). Artful Science: Enlightenment Entertainment and the Eclipse of Visual Education. Cambridge, MA: The MIT Press.

The Algal World


Anna Atkins, Confervae, Cyanotype. Digital image courtesy of the Getty’s Open Content Program.

A recent Twitter post from the Manchester Museum Herbarium said that they were getting ready for a tour; attached was a photo of a seaweed album and specimen. This reminded me that I was lured into the herbarium world by just such material. I was on a tour given by the curator of collections, Marilyn Massaro, at the Roger William Natural History Museum in Providence, Rhode Island. The museum has a 6,000-specimen herbarium, most dating from the late 19th and early 20th centuries; it is like a botanical time capsule of the period. Rhode Island has so much coastline, it’s not surprising the collection includes seaweed albums, since creating them was a popular pastime in the 19th century, especially among women. It was considered ladylike to collect plants, and many macroalgae are so aesthetically pleasing that they were particularly attractive specimens. Blank albums were even sold for collections created on vacation. When Dr. Massaro showed us several of these books, I was fascinated by them. When I returned home, I tried to learn more about herbaria, and this became a long-term obsession with them, which, in turn, led to this blog.

I returned to Providence several months later for a better look at the collection, and Dr. Massaro showed me related archival material. This included a 1926 letter from William L. Bryant, the museum director at the time, to Mrs. George P. Wetmore of Newport thanking her for the collection of sea mosses she had donated. This is one in a series of letters among Bryant, Mrs. Wetmore, and her daughter, Edith Wetmore. When Edith sent the album, she asked Bryant to thank her mother. He wrote back asking for her mother’s name so he could thank her properly. Edith responded in another handwritten note saying: “It did not dawn on me that you would not know that, coming as the album did from Newport, you could only have received it from Mrs. George Peabody Wetmore.” George Peabody Wetmore was governor of Rhode Island from 1885-1887, and Edith obviously assumed that his name would still be familiar to all 40 years later. As a final point, Edith mentioned that this collection was originally offered to the Children’s Museum in Newport, but they already had such an album and thought it should go to a “bigger institution.” This suggests two things: that they knew the Wetmore name, and that such albums were common at the time. I now appreciate the latter fact because most herbaria in coastal areas in the US and Britain boast these collections. They are hardly a rarity, even though preparing specimens required a certain skill. Some are now considered more as works of art.

Unlike terrestrial plants, seaweeds don’t have much rigid structural material, so they are limp once removed from water. The trick to mounting them is to slip a sheet of stiff paper under a specimen floating in water and then raise the sheet with the plant spread upon it. There is enough sticky material on the plant’s surface that it doesn’t have to be pasted down. It will adhere to the paper, and voila, there is a herbarium specimen—or an album page. With a little practice, this technique works remarkably well and results in beautiful specimens, with all the delicate filigree of the algae artistically arranged. It is no wonder that seaweed albums became such a fad.

But interest in macroalgae was really more than a fad, it was a serious area of study for many professional and amateur botanists. The leader of the pack was probably William Henry Harvey (1811-1866), an Irish botanist who wrote extensively on algae, producing definitive works on British, North American, and Australian species. While in Australia he collected numerous specimens of each species in order to finance his trip, writing that he intended to create 50 collections, with 200 to 600 specimens in each. From the number of Harvey specimens in the US, Britain, and Australia, he must have come close to reaching his goal. Even the small William Darlington Herbarium at West Chester College in Pennsylvania has 272 sheets, and Darlington wrote to John Torrey that he had heard about Harvey’s lectures in Boston, so the Irishman’s trip to the United States was a noteworthy botanical event.

Like all industrious botanists of the time, Harvey maintained a large network of correspondents who could provide him with information and with specimens. It would be difficult to find an algologist of that period who did not have contact with him. Since he was working at the same time that seaweed collecting was popular, many of these individuals were women, some of whom were as passionate and hardworking as himself. Amelia Griffiths (1768-1858) collected along Britain’s western coast and sent materials to Harvey. She was assisted by her maid Mary Wyatt, who under Griffiths’s guidance produced bound volumes of mounted of Devon algae (1834-1840) to which Harvey referred his readers when he published his unillustrated Manual of British Flora (1841). Margaret Gatty (1809-1873), who wrote nature books for children particularly about the seaside, was serious about algae and her herbarium of 8000 specimens, which includes specimens sent by Harvey, is preserved at St. Andrew’s University in Scotland. Among the most impressive presentations of seaweed was that of Anna Atkins who created Photographs of British Algae (1843-1853), a collection of blue cyanotypes, one of the earliest versions of photographs [see Figure].

At Cambridge University Herbarium, there is a collection of hundreds of watercolors of macroalgae, amazingly beautiful and accurate. They were done by Mary Philadelphia Merrifield (1804-1889), an artist who was originally attracted to seaweed for their beauty, but then went on to study them seriously, publishing several scientific articles. When I visited Cambridge, Christine Bartram, the chief herbarium technician, showed me the paintings and told me about discovering them. Shortly after the collection was moved into a new building, Bartram had an inquiry about Merrifield from someone who had bought a house, found Merrifield letters there, and was curious about her. Bartram recalled that during the move she had seen a shoebox marked “Merrifield,” was able to hunt it down, and found the watercolors. Now they are being preserved more fittingly and being studied.

Before I leave the 19th century, I must mention Ellen Hutchins (1785-1815), who has been called Ireland’s first female botanist. She is at the early end of the seaweed craze and lived near the coast in Cork. Like many at the time, she was encouraged to take up nature study as a healthy hobby by a physician in Dublin where she had been sent to convalesce. Though she was never robust and died young, she wholeheartedly devoted herself to botany under the tutelage of James Mackay, curator at the Botanic Garden of Trinity College, Dublin. He suggested that she study seaweeds when she returned home to Cork, and most of her collections are from the Bantry Bay area. He also put her in touch with the algologist Dawson Turner, with whom she exchanged information and specimens, some of new species. As well as preparing specimens, she produced accurate drawings and watercolors. Hutchinson was known for being able to find and correctly identify rare species. Her specimens are now primarily in the Natural History Museum, London, and most of her drawings are at the Royal Botanic Gardens, Kew.

Though it pains me leave seaweed hunters and the 19th century here, I must in order to move on to other wonders of the algal world, including diatoms, the subject of the next post.

Atkins, A. (1843-1853). Photographs of British Algae: Cyanotype Impressions (Vol. 5 volumes).

Harvey, W. H. (1849). A Manual of British Algae. London: van Voorst.

Wyatt, M. (1834-1840). Algae Danmonienses. Torquay: Cockrem.

Uses of Herbaria: There Are Still More . . . .


WeDigBio is a program to encourage citizen scientists to participate in specimen digitization projects

Before I began this set of posts on uses of herbarium specimens, I wrote several on employing herbaria in the study of history. I want to return to history here, but in a different way, namely botanical collections as cultural heritage. I first became aware of this topic when I heard Krishna Shrestha, a Nepalese botanist, speak at the 2011 International Botanical Congress in Melbourne, Australia. He was a curator at the National Herbarium in Nepal and was arguing for the importance of digitizing collections as a way for botanists in developing nations like his own to have access to specimens that had been collected by colonial powers and sent to their home countries without leaving duplicates behind. This practice is long gone thanks to both national and international regulations on collecting, but the results of past practices linger. The largest collections of Nepalese material are in Kew, Edinburgh, Calcutta, and Japan. The Nepal herbarium started in 1940 so all their specimens are from after that date. The herbarium now has about 150,000 specimens, but Japan alone had 160,000 Nepalese specimens. In Africa the same problem exists. As an example, for the Rubiaceae family with 13,000 species in 611 genera, Europe has only 14 genera while Angola has 108. However, European herbaria hold 96% of the types for this family (Figueiredo & Smith, 2010).

The Global Plants Initiative, funded by the Andrew W. Mellon Foundation, has had types specimens from all over the world scanned and the label information digitized in an effort to deal with this situation. Still, digital access is not the same as having specimens available close at hand. Individuals in many countries are realizing the value of the material, though in some cases it is no longer available. For example, historic plant specimens collected in the early 20th century in Korea were destroyed during the Korean War (Im et al., 2016). Now botanists are examining duplicates housed in the herbarium of the University of Tokyo, which survived World War II. A set of duplicates was donated to Korea by the Japanese, so some Korean botanical history has been restored. There is work being done at the herbarium in Uzbekistan on the flora of that country (Sennikov et al., 2016) and the Regnellian Herbarium in Stockholm is working with Brazilian botanists in electronic “repatriation” of Brazilian specimens collected by Swedish botanists in the late 19th and early 20th centuries (Santos & Santos, 2016). Alarmed by the loss of a number of species of medicinal fungi from Indian forests, the National Fungal Culture Collection of India is augmenting its specimen collection through its own collecting efforts.

In an intriguing use of specimens, researchers have done genetic analysis of the paper mulberry, a common East Asian tree that was carried to the islands of Oceania where it became a source of barkcloth, a significant element in Austronesian cultures (Chang, et al., 2015). The aim of the study was to see if genetic studies could trace the origin of the tree and thus hint at the origin of the original settlers. This is a debated question with evidence in favor of Taiwan as the home country, but with other hypotheses seeing the origin in South China or even further into Southeast Asia. The mulberry data point to Taiwan as the home base for these explorers, since the trees in Oceania are most similar to those on the island than to those on the Chinese mainland or elsewhere. I’m sure this won’t end the controversy but it does suggest a new use for herbaria to add to Vicki Funk’s list. In addition, archaeologists have frequently examined herbarium specimens to aid in identification of plant material found at a site and paleobotanists compare their finds with present-day specimens in terms of such characteristics as leaf venation (Coiffard & Mohr, 2016).

I’m skipping around in this post, but there are so many ways to use specimens, and more are being devised thanks to digitization of specimens. In what may develop into a major focus, researchers in Germany have used the high-resolution images of specimens of 26 species of German trees to test attempts at automated identification (Unger et al., 2016). There were problems, overlapping leaves being a major one. However, they found that they could characterize species well enough for identification in a significant number of cases. In the future, they see such a system as being able to rapidly identify at least frequently collected taxa. It will be interesting to see if this technology will ever play a significant role in taxonomic research. I can’t resist mentioning another novel use: Alfred Traverse (2013) suggests that herbarium specimens can be a source of soil on the roots. Since I’ve spent some time mounting specimens and attempting to remove as much soil as possible, as per instructions, I’m left wondering what is the right approach here.

I’d like to end this litany with a brief mention of education. It’s obvious that herbaria are key in the development of the next generation of plant taxonomists, and as some of the research cited in these posts suggests, future ecologists and environmentalists as well. But I am thinking of those in high school and even elementary school. In the past, their exposure to such institutions has been almost nil. But herbarium administrators are now realizing that if these collections are to remain relevant into the future, a wider audience is needed. Tours of herbaria for people of all ages are becoming more common, and some are geared to a young audience. A number of herbaria have taken advantage of the Harry Potter craze to stage events focused on plants featured in some of the potions used at Hogwarts. Other herbaria have taken part in the WeDigBio events where high school students participate in digitization of specimen labels. Such activities get young people into a new world to which some of them may return in the future. Not a bad use for a herbarium.


Chang, C.-S., Liu, H.-L., Moncada, X., Seelenfreund, A., Seelenfreund, D., & Chung, K.-F. (2015). A holistic picture of Austronesian migrations revealed by phylogeography of Pacific paper mulberry. Proceedings of the National Academy of Sciences, 112(44), 13537–13542.

Coiffard, C., & Mohr, B. (2016). Afrocasia kahlertiana gen. et sp. nov., a new tropical member of Araceae from Late Cretaceous strata of northern Gondwana (Baris, Egypt). Taxon, 65(6), 1374–1384.

Figueiredo, E., & Smith, G. F. (2010). The colonial legacy in African plant taxonomy. South African Journal of Science, 106(3/4), Article 161.

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.

Santos, K. dos, & Santos, K. dos. (2016). Brazilian plant specimens at the Regnellian herbarium: history and repatriation. Rodriguésia, 67(4), 879–892.

Sennikov, A. N., Tojibaev, K. S., Khassanov, F. O., & Beshko, N. Y. (2016). The Flora of Uzbekistan Project. Phytotaxa, 282(2), 107–118.

Traverse, A. (2013). Dr. Pugh’s herbarium. Journal of the Botanical Research Institute of Texas, 7(2), 751–764.

Unger, J., Merhof, D., & Renner, S. (2016). Computer vision applied to herbarium specimens of German trees: Testing the future utility of the millions of herbarium specimen images for automated identification. BMC Evolutionary Biology, 16, 248.

Uses of Herbaria: Environmental Studies


Online herbarium of the Australian Centre for Mined Land Rehabilitation

As I discussed in the previous post, there is a great deal of evidence for change in phenology and other plant characteristics as a result of climate change. Here I want to consider other types of specimen information related to environmental change that can improve our understanding. For example, long-term herbarium data reveal a decline in temperate-water algae at its southern range (Riera et al., 2015). On dry land, a massive analysis of a database with two million specimens from a network of 35 Californian herbariums revealed that species are moving northward, but not at the same rate. In particular, animal populations are adjusting to temperature rise more rapidly than plants. This isn’t surprising, but it means that food webs are likely to be disrupted. In a very different kind of study, Swedish researchers compared photosynthesis products in 100-year-old herbarium specimens versus recently collected ones and detected a difference in the balance between photorespiration and photosynthesis. Again, it is not surprising that there was discovered an increase in photosynthesis relative to photorespiration; this would be expected as CO2 levels rise, but it does provide a very different type of evidence, thus strengthening the climate-change argument.

Unfortunately, there are many other environmental problems. Specimens can supply crucial data in these areas as well. Ecologists employed niche modeling tools combined with herbarium occurrence records to estimate the global invasive potential of each of 10 species of parasitic witchweeds in the family Orobanchaceae (Mohamed et al., 2006). Results show that these notorious weeds have significant invasive potential not only in tropical and subtropical areas, but in temperate ones as well. There have already been a number of large-scale control and eradication efforts, and perhaps these predications will lead to earlier and more effective interventions. A number of European groups have studied the genetics of the ragweed, Ambrosia artemisiifolia, which is native to the Americas but is now widespread in Europe. By comparing genes in old herbarium specimens and more recent collections in Italy, France, and Spain, geneticists are beginning to be able to identify more recent populations, and those that have interbred with older ones. It is fascinating how such comparisons can fill in stories about species movements in ways that just looking at more recent collections can’t (Chun et al., 2010).

Not only invasions can be tracked with specimens but infestations as well. The most spectacular story, at least from the viewpoint of someone of Irish descent like myself, is the discovery of the strain of Phytophthora infestans responsible for the potato late blight that caused the famine in Ireland in the mid-1840s (Goss, et al., 2014). It was possible to retrieve specimens of the pathogen from Kew herbarium sheets of potato plants collected in Ireland at the time. DNA sequencing indicates the origin of the pathogen was from a Mexican strain rather than an Andean one. This is significant not only for solving a historical puzzle but for understanding how these pathogens spread from their areas of origin. Since phytophthora remains the leading cause of potato crop destruction, the study is important for the future as well.

The larva of the moth Cameraria ohridella is a leaf-miner feeding on horse chestnut trees in Europe. It was first noted in Austria in 1984 and was declared a new species in 1986. It’s now becoming more and more common throughout Europe, but where it originated was something of a mystery. One place to look for clues would be in herbaria, and when horse chestnut specimens at several European collections were examined, horse chestnut leaf damage by this species was found on leaves in the Kew herbarium collected from natural populations in Greece as early as 1879. This is a significant finding, but who knows what more searches may turn up. The authors note: “This case history demonstrates that herbaria are greatly underutilized in studies of insect–plant interactions, herbivore biodiversity, and invasive species’ origins” (Lees et al., 2011, p. 322).

The types of research I’ve been discussing are why large-scale digitization of specimens has been funded. Herbarium sheets supply data on environmental change that just can’t be acquired in any other way. Herbaria are also used by many who are not doing research, but rather are involved in creating and enforcing environmental regulations at the federal, state, and local levels. For example, the Centre for Mined Land Rehabilitation in Australia maintains a herbarium to aid in the assessment of the environmental effects of mining and of successes in rehabilitating disturbed lands. Plant identification is crucial to this work, and there is nothing better than vouchered specimens for the purpose.

Mark Elvin of the US Fish and Wildlife Service, who is involved in conserving aquatic plant species, notes that digitization of specimens has improved the basis for decision making related to the laws and regulations that the service administers including the Endangered Species Act and the Convention on International Trade in Endangered Species (CITES). With digitization, information can be obtained faster, and more thorough data searches can be done. Willem Coetzer (2012) reports from South Africa that herbaria there are involved in projects dealing with bioregional planning, developing sustainable harvesting programs, preparing environmental impact assessments, and doing ecological niche modeling. The same could be said for many herbaria worldwide, and as more data becomes available online these uses will only grow more important.

It might seem at this point that there couldn’t be any further ways that herbaria can be useful, but that’s just not the case. In the next post, I’ll finish up this review by looking to other fields that are beginning to see herbaria as mines of information and inspiration.


Chun, Y. J., Fumanal, B., Laitung, B., & Bretagnolle, F. (2010). Gene flow and population admixture as the primary post-invasion processes in common ragweed (Ambrosia artemisiifolia) populations in France. New Phytologist, 185(4), 1100–1107.

Coetzer, W. (2012). A new era for specimen databases and biodiversity information management in South Africa. Biodiversity Informatics, 8(1). Retrieved from

Goss, E. M., Tabima, J. F., Cooke, D. E. L., Restrepo, S., Fry, W. E., Forbes, G. A., … Grünwald, N. J. (2014). The Irish potato famine pathogen Phytophthora infestans originated in central Mexico rather than the Andes. Proceedings of the National Academy of Sciences, 111(24), 8791-8796.

Lees, D. C., Lack, H. W., Rougerie, R., Hernandez-Lopez, A., Raus, T., Avtzis, N. D., … Lopez-Vaamonde, C. (2011). Tracking origins of invasive herbivores through herbaria and archival DNA: The case of the horse-chestnut leaf miner. Frontiers in Ecology and the Environment, 9(6), 322–328.

Mohamed, K. I., Papes, M., Williams, R., Benz, B. W., & Peterson, A. T. (2006). Global invasive potential of 10 parasitic witchweeds and related Orobanchaceae. Ambio, 35(6), 281–8.

Riera, R., Sangil, C., & Sansón, M. (2015). Long-term herbarium data reveal the decline of a temperate-water algae at its southern range. Estuarine, Coastal and Shelf Science, 165, 159-165.

Uses of Herbaria: Biogeography and Climate Change


iDigBio is an NSF-funded program to digitize US natural history collections

Alexander von Humboldt (1759-1769) is often considered the father of biogeography because of his crucial work on this subject in South America, and his writings and diagrams showing the link between terrain and vegetation (Humboldt & Bonpland, 2009). However, even during the Renaissance it was becoming obvious that terrain and climate greatly influence plant life. Many of the plants of northern Europe turned out to be different from the Mediterranean plants described by ancient authors including Theophrastus and Dioscorides. Place mattered and as botanists went on field trips and collected specimens, they become more aware of local differences in plant habitats. Now plant distribution is a major focus for botanists and ecologists, and herbaria are important in documenting what grows where. Species distribution maps are a staple of floras.

Today, with the combination of GPS coordinate mapping and digitization of specimen data, it’s possible to generate distribution maps relatively easily from online herbarium data. However, there is a question as to how accurate these maps are. As with any output, the answer depends upon the input: the accuracy of the localities. There is software such as GEOLocate and the MaNIS Calculator that will generate the probability of a plant being within a particular radius. Doing georeferencing well is time-consuming, and there are millions of sheets requiring attention. Even if all the data were optimal, there is the question of what percentage of the sheets are available online? If the species distribution maps are based on online data, and that only represents, say, a quarter of the specimens, then how accurate is it? In addition, there is collection bias. In other words, rarely are regions sampled uniformly. Studies show that areas accessible via roads, rivers or railroads are more likely to be thoroughly canvased than are more remote locales, so all the error can’t be blamed on computers (Vetter, 2016). Some of the best studies are those that combine herbarium data with direct observation in an area (Martin et al., 2014; Mohandass & Campbell, 2015).

At the present there can’t be any discussion of biogeography without bringing up climate change. At the moment, interest in this topic is driving not only research on herbarium collections but also their digitization. Herbaria are among the few places where there are records that range over more than 100 years, in some cases 200-400 years, and they become more valuable by the day. Records can be studied in a variety of ways to glean information on climate and habitat characteristics in the past. The area that has been developed most substantially is phenology, the study of natural events that can be pinpointed in time. For plants this is often budding, flowering, or seed setting. Though this has not always been true in the past, it is now standard herbarium practice to collect specimens that are in flower or have seeds or fruit. Since collection data are always recorded for specimens, researchers can track flowering or fruiting over the years to detect differences that might be related to climate change. Again, if digitized and imaged specimens are used, the study is limited by the richness of the sample, but it does make for more efficient investigation. There have been several studies validating the methods used in this research (Davis et al., 2015; Spellman et al., 2016). To date, changes in flowering times have been noted in orchids (Molnar et al., 2012), eucalypts (Rawal et al., 2014), and perennial herbs (Matthews & Mazer, 2015) among others; changes were also recorded in leaf-out times for trees (Everill et al., 2014; Zohner & Renner, 2014). With projects like NSF’s iDigBio, which has resulted in a portal with access to over 75 million natural history specimens, the problems of small sample sizes are dwindling, but still significant.

Still other ways to document climate change with specimens include counting the stomata on leaves. This is obviously more time-consuming, but the number of studies in this area suggest that it’s considered a fertile area of investigation. Stomata are the pores in a leaf through which plants absorb CO2, the fuel for photosynthesis. Since global warming is precipitated by the increase in atmospheric CO2 due to fossil fuel combustion, it’s not surprising that in several species, there has been a decrease in stomatal density. Plants just don’t need as many pores to absorb the same amount of CO2. In addition, leaves can give evidence of other types of environmental change. An alteration in leaf area over the past three centuries has been noted for some species (Peñuelas & Matamala, 1990). Also, there was a marked decrease in leaf sulfur levels in the years after the clean air act was passed and an increase in nitrogen with increased use of fertilizers (Peñuelas & Filella, 2001). Someone has even studied the distance over time between leaf teeth in the mulberry Hedycarya angustifolia over the past 160 years to see if an increase in temperature had affected this trait. However, despite the painstaking analysis, researchers couldn’t find any significant change (Scarr & Cocking, 2014). This work shows how many ways climate change can affect plants, and how clever botanists and ecologists employ varied plant characteristics in collecting data on this phenomenon. Having different types of data strengthens the case for the significant impact of climate on plant growth and also on the survival of species. I’ll present more evidence for this in the next post.


Davis, C. C., Willis, C. G., Connolly, B., Kelly, C., & Ellison, A. M. (2015). Herbarium records are reliable sources of phenological change driven by climate and provide novel insights into species’ phenological cueing mechanisms. American Journal of Botany, 102(10), 1599–1609.

Everill, P. H., Primack, R. B., Ellwood, E. R., & Melaas, E. K. (2014). Determining past leaf-out times of New England’s deciduous forests from herbarium specimens. American Journal of Botany, 101(8), 1293–1300.

Humboldt, A. von, & Bonpland, A. (2009). Essay on the Geography of Plants. (S. T. Jackson, Ed., S. Romanowski, Trans.). Chicago, IL: University of Chicago Press.

Martin, M. D., Zimmer, E. A., Olsen, M. T., Foote, A. D., Gilbert, M. T. P., & Brush, G. S. (2014). Herbarium specimens reveal a historical shift in phylogeographic structure of common ragweed during native range disturbance. Molecular Ecology, 23(7), 1701-1716.

Matthews, E. R., & Mazer, S. J. (2015). Historical changes in flowering phenology are governed by temperature × precipitation interactions in a widespread perennial herb in western North America. The New Phytologist, 210(1), 157-167.

Mohandass, D., & Campbell, M. J. (2015). Assessment of Roscoea population size in the Central Himalayas based on historical herbarium records and direct observation for the period 1913-2011. Journal of Biological Records, 0022015, 10–16.

Molnár, A., Tökölyi, J., Végvári, Z., Sramkó, G., Sulyok, J., Barta, Z., & Bronstein, J. (2012). Pollination mode predicts phenological response to climate change in terrestrial orchids: A case study from central Europe. Journal of Ecology, 100(5), 1141–1152.

Peñuelas, J., & Filella, I. (2001). Herbaria century record of increasing eutrophication in Spanish terrestrial ecosystems. Global Change Biology, 7(4), 427–433.

Peñuelas, J., & Matamala, R. (1990). Changes in N and S leaf content, stomatal density and specific leaf area of 14 plant species during the last three centuries of CO2 increase. Journal of Experimental Botany, 41(9), 1119–1124.

Rawal, D. S., Kasel, S., Keatley, M. R., & Nitschke, C. R. (2014). Herbarium records identify sensitivity of flowering phenology of eucalypts to climate: Implications for species response to climate change. Austral Ecology, 40(2), 117-125.

Scarr, M. J., & Cocking, J. (2014). Historical responses of distance between leaf teeth in the cool temperate rainforest tree Austral Mulberry “Hedycarya angustifolia” A. Cunn. from Victorian herbarium specimens. Victorian Naturalist, 131(2), 36–39.

Spellman, K. V., & Mulder, C. P. H. (2016). Validating herbarium-based phenology models using citizen-science data. BioScience, 66(10), 897–906.

Vetter, J. (2016). Field Life: Science in the American West during the Railroad Era. Pittsburgh, PA: University of Pittsburgh Press.

Zohner, C. M., & Renner, S. S. (2014). Common garden comparison of the leaf-out phenology of woody species from different native climates, combined with herbarium records, forecasts long-term change. Ecology Letters, 17(8), 1016-1025.

The Myriad Uses of a Herbarium


Type specimen of Altamiranoa elongata from the US Herbarium, Smithsonian Institution

When it comes to discussing the uses for plant specimens, you can’t do better than refer to Vicki Funk’s classic 2004 article “100 Uses for an Herbarium (Well at Least 72).” It is thorough and succinct. So why am I bothering to write on the same topic, if Funk has covered it so brilliantly? Well, that would deprive me of the fun of exploring some of those uses in a little more detail and perhaps even unearthing one or two new ones. While service to botany may seem the obvious place to begin, I’m going to start with medicine, the field that prompted the creation of the first documented herbarium, that of the Italian botanist and professor of medical botany, Luca Ghini (1490-1556), founded the first botanical garden at Pisa. The garden was designed to introduce students to the plants that were used by apothecaries, so they would be able to recognize them. This was obviously the function of the herbarium as well, and several of Ghini’s students, including Andrea Cesalpino (1519-1603) and Ulisse Aldrovandi (1522-1605) created specimen collections that exist to this day. Apothecaries also took up the practice, with Hieronymus Harder (1523-1607) creating a dozen bound herbaria, eleven of which are still extant.

The link between herbaria and medicine continues to this day. Those doing research on herbal medicines are often required to create voucher specimens of the plants they are studying so others can verify the identification in the future (Eisenman et al., 2012). One problem in past research was the difficulty of getting consistent results from one batch of plant material to the next. Having some of the material itself preserved in a voucher makes it easier to check whether or not the same species, subspecies, or variety was used in both cases. Not only can the plants be visually examined, but chemical tests can be done on the material if necessary. Rainer Bussmann has a chapter on “Taxonomy—An Irreplaceable Tool for Validation of Herbal Medicine” if you would like to learn more on this topic.

Voucher herbarium specimens are required in almost all botanical research, because the plant itself is the best evidence for answering questions about what species was actually growing where at a particular time. The most valuable kind of voucher is the type specimen, the record of the plant that was used in describing the species for the first time. Since modern taxonomy dates back to the publication of names by Carl Linnaeus in Species Plantarum in 1753, it is no wonder that the material he studied is itself still being tracked down to give as full a record as possible of the plant specimens, and in some cases plant images, upon which he based his descriptions (Jarvis, 2007). To this day, journals such as Taxon require authors to list specimen numbers and the herbaria where they are located for all material studied in revising taxa.

With the advent of DNA sequencing, herbarium vouchers can now be used in an entirely new way. A small piece of a specimen may yield enough intact DNA for researchers to identify a species with DNA sequencing. There are a number of factors limiting success including age, method of preparation, and species, but there are now many papers documenting the reliability of the results. The rich information the studies can yield include improvement in the fungal phylogenetic tree (Dentinger et al., 2015), tentatively identifying plants on Linnaeus’s Hamerby’s estate as related to his type specimens (Andreasen et al., 2014), and employing herbarium specimens in large-scale genomics research.

There are also more conventional uses of specimens that are nonetheless critical to botany. The development of floras—lists of plants in a particular locale—are impossible without using herbaria for collecting information. And when botanists are looking for living specimens of a species, the logical place to begin is in the herbarium where they can discover the location of past collections for the plant in question. The Royal Botanic Gardens, Kew (Kew) produces seed collecting guides for botanists going to areas such as Mozambique. The guides include descriptions of each species with a photo of the herbarium sheet as well as of the live plant. Specimens also can be used to hunt for other things besides plants, like diamonds and gold. The palm-like plant, Pandanus candelabrum is rare because it only grows in soils containing kimberlite which is rich in magnesium, potassium, and phosphorus. Kimberlite is also the volcanic rock where diamonds are found. So P. candelabrum, which grows in Liberia, may make it a little easier to discover these gems. As for gold, particles of the metal in Eucalyptus specimens may indicate gold deposits in the area where the trees grew. Using this link to direct prospecting is still experimental. It is definitely a long way from panning for gold, but worth a try (Lintern et al., 2013). These are very specific examples of botanical biogeography, but this is a much broader topic that I’ll discuss in my next post.


Andreasen, K., Manktelow, M., Sehic, J., & Garkava-Gustavsson, L. (2014). Genetic identity of putative Linnaean plants: Successful DNA amplification of Linnaeus’s crab apple Malus baccata. Taxon, 63(2), 408–416.

Dentinger, B. T. M., Gaya, E., O’Brien, H., Suz, L. M., Lachlan, R., Díaz-Valderrama, J. R., … Aime, M. C. (2015). Tales from the crypt: genome mining from fungarium specimens improves resolution of the mushroom tree of life. Biological Journal of the Linnean Society, 117(1), 11-32.

Eisenman, S., Tucker, A., & Struwe, L. (2012). Voucher specimens are essential for documenting source material used in medicinal plant investigations. Journal of Medicinally Active Plants, 1(1), 30–43.

Jarvis, C. (2007). Order Out of Chaos: Linnaean Plant Names and Their Types. London, UK: Linnaean Society.

Lintern, M., Anand, R., Ryan, C., & Paterson, D. (2013). Natural gold particles in Eucalyptus leaves and their relevance to exploration for buried gold deposits. Nature Communications, 4, 2274.

History and Herbaria: Dream Digital Projects


Nathaniel Wallich Website

In the last post, I discussed portals presenting historical plant collections and related correspondence. Now I want to describe my dreams of future projects. Think of how exciting it would be to map all of the Hooker’s correspondence as well as those of George Bentham, Asa Gray, and John Torrey. The intricacy of such a network would be an amazing display and would, I suspect, reveal previously unexplored connections. Ronald McColl, a librarian, has created network maps of correspondents for the Pennsylvania botanist William Darlington (1782-186), and it reveals a rather impressive set of botanical notables including not only Englemann, Gray, and Torrey, but also Jacob Agardh in Sweden, William Hooker, and Alphonse Pyramus de Candolle in Geneva. While Darlington is hardly a major figure in American botany, these diagrams reveal just how broad his network was, and his letter books indicate how hard he worked to develop it—offering to send specimens and publications in return for the same. McColl’s work suggests what can be done to present botany and history digitally.

Europeana is a massive portal that links science and humanities collections in museums and libraries throughout Europe, so searching for example for “iris” can yield links to art, as well as to scientific information on the species, reminding users about the connections among disciplines that many searches reveal. The Digital Library of America may one day provide some of the same power. However, my dream portals would be more circumscribed. For example, Linnaeus’s specimens at the Linnaean Society and other locations linked to the analysis of Linnaean type specimens in Jarvis’s Out of Chaos (2007) Some of the types are illustrations, so they would also be available. And while I am dreaming I’d like to be able to follow that trail to what has happened to these names up to the present day.

The thousands of images created by local artists during the Spanish Royal Botanical Expedition to New Granada (1783-1816) headed by José Celestino Mutis are available on a website hosted by the Real Jardín de Botánico in Madrid, but it would be interesting to see how these illustrations are tied to information about the species portrayed. The botany behind the expedition is complex and involves botanists not only in South America and Spain, but in Switzerland and the United States as well. This is an example of an endeavor that would be difficult for more than technological reasons.

I would also love to see work building on the Lewis and Clark material that is already online, thanks to the work of the Academy of Natural Sciences (ANS) in Philadelphia, which holds an impressive collection of these specimens. In addition, James Reveal and his colleagues have made a great deal of information about the expedition available on the web, including photographs of the plants. If more botanical illustrations of the same species as well as the current literature on them, from for example, the Flora of North America, could be added, the visual, historical, and scientific value of the site would indeed be powerful. The same goes for the John Bartram specimens in the NHM, and in a more unlikely place, the Sutro Library in San Francisco, which holds the 16-volume herbarium of Lord Robert Petre, one of Bartram’s patrons. Several of the volumes contain Bartram plants, some with short notes he added to describe where he found the specimen or why he considered it of interest. At the moment, the Sutro material hasn’t been digitized, but it would be valuable addition to what is available electronically about John Bartram, his travels, his collections, and his economic dealings with British botanists and horticulturalists. If this were tied to images and transcripts of his correspondence with the primary British patron and fellow Quaker, Peter Collinson (1694-1768), and to the art and writings produced by his son, William Bartram (1739-1823), the portal would make a major contribution to American history as well as to botanical history.

It is not only figures of the rather distant past who could benefit from such internet attention. NYBG has created a portal, the Barneby Digital Monograph and Specimen Catalog, with links to both the material the garden’s botanist Rupert Barneby wrote on legumes and to relevant specimens. This is obviously of taxonomic importance, but it also contains important information on how plant science was done in the mid-20th century that can be studied alongside books such as Douglas Crase’s (2004) biography of Barneby and his partner, Dwight Ripley. It serves as a model for other such projects. But what concerns me is the difficulty of meshing resources that have been put online in different formats. The Barneby material was primarily from NYBG, and much of it was digitized for this project, but I again return to the problem of standardization in the handling of digitization. Things are definitely moving in this direction, but it is a laboriously process and that’s why theoretical and technical work in bioinformatics is so important to the future of digital information. It will be interesting to see how things evolve over the next few years. Right now, the emphasis within the natural history collection community is primarily on the scientific value of its collections, but hopefully the viewpoint will become more inclusive. I myself am involved in a project that brings scientists, historians, educators, and literary scholars together with garden enthusiasts to create a portal that will be of interest to all these constituencies. More will be forthcoming on this as the project gets underway later this year.

Brunfels, O. (1530). Herbarum Vivae Eicones. Strassburg, HRE: J. Schott.

de Koning, J., van Uffelen, G., Zemanek, A., & Zemanek, B. (Eds.). (2008). Drawn After Nature: The Complete Botanical Watercolours of the 16th-Century Libri Picturati. Zeist, the Netherlands: KNNV Publishing.

Haygood, T. M. (1987). Henry William Ravenel, 1814-1887: South Carolina Scientist in the Civil War Era. Tuscaloosa, AL: University of Alabama Press.

Sloane, H. (1707). Natural History of Jamaica (Vol. I). London, UK: British Museum.

Sloane, H. (1725). Natural History of Jamaica (Vol. II). London, UK: British Museum.

History and Herbaria: Other Digital Projects



Botanica Caroliniana Website

As promised in the previous post, here are several projects combining herbarium collections and history. The Bergerbibliothek in Bern, Switzerland has an impressive website for its collection of Felix Platter material. Platter (1536-1614) was a noted physician and botanist who had an extensive herbarium now available on this site. What is even more striking is the collection of illustrations he amassed, including some of the original watercolors done by Hans Weiditz for Otto Brunfels’s groundbreaking herbal of 1530. These drawings were painted on both sides of a page, and Platter wanted to file them according to species, which meant that he or one of his assistants cut out each drawing in an attempt to have good representations of both species that could be filed separately. These were then pasted to individual sheets of paper. Now all of this is available online, giving a good sense of Weiditz’s artistry, if in a somewhat odd format. This questionable treatment does indicate how important Platter considered illustrations in the study of plants at this time, and it’s this valuing that allowed these masterpieces to be preserved. In the many volumes of the Platter herbarium there are also woodcuts and other illustrations. Now all these are searchable, and the specimens and illustrations of a species can be seen at the same time. This was a massive effort and a beautiful result because the Bergerbibliothek’s Platter site also has information on the provenance of the collection and the restoration project to stabilize the volumes.

As you might suspect, I am partial to Renaissance collections and grateful to those European institutions such as the libraries in Erlangen and Bern that have made them freely available. At the Jagiellon Library in Krakow, the Libri Picturati, a collection of botanical illustrations related to Carolus Clusius, has also been published in book form (de Koning et al, 2008), but it’s not yet available electionically. As more of these treasures receive attention, it would be wonderful to have a portal that made them all searchable at the same time, so a user could see how a particular species is treated by a variety of different artists, along with related specimens (A portal like this exists for European cabinets of curiosities). In some cases, as with the Jamaican plants in the Hans Sloane Herbarium at the NHM, the illustrations made by Everhardus Kickius for Sloane’s volumes (1707, 1725) on Jamaica are very similar to the specimens. This is easy to see because the specimen and watercolor are set right next to each other on opposite pages of the bound volumes of his herbarium. The Sloane Herbarium site is searchable, if you know a genus or species you want to see. This type of portal is designed more for biologists than for historians and brings up the issue of how design can limit or discourage access to a site.

Another important project is Botanica Caroliniana, a collaboration between Furman and Clemson Universities. Several historical collections related to the Carolinas have been put online. The first was the Catesby collection of specimens in the Sloane Herbarium at the NHM in London. Each specimen is presented opposite the page in Catesby’s Natural History of the Carolinas that depicts the species, with the accompanying text also displayed. This is a great example of what digitization makes possible: the juxtaposition of images and text from a rare book with specimens from a priceless herbarium. History, botany, art and literature are all involved, and the project was done by institutions of the region of origin of many of the specimens, so it speaks to environmental conservation and respect for the nature of the area.

Another project from South Carolina called Plants and Planter deals with the work of the botanist Henry Ravenel (1814-1887). It presents Ravenel’s specimens and journals, along with journal transcripts. Several institutions— South Carolina University Library, A. C. Moore Herbarium, Clemson University, Converse College, and the University of North Carolina Wilson Library—contributed materials, bringing them together in a searchable format. Some of the specimens on this website were scanned as part of the Advancing Digitization of Biological Collections (ADBC) project. This is a massive NSF-funded effort to digitize biological specimens at non-federally sponsored institutions and suggests that these efforts have more than scientific value. Ravenel collected before, during, and after the Civil War, so historically his work is significant. He eventually focused on fungi, and particularly after the war he made large collections that he sold as a way to improve his economic condition. He is considered one of the most significant students of fungi in the 19th century (Haygood, 1987).

There are other collections that could benefit from this type of presentation. Asa Gray’s papers at Harvard have been digitized, and some of them transcribed. Many of the specimens he used in his work have also been digitized at Harvard. However, it would be a massive undertaking, involving very different databases, to create a portal where specimens could be called up with the corresponding text, even though the two collections are physically close together. It’s obvious from the examples of Sloane and Gray, that physical and electronic proximity are very different things. But that doesn’t mean that this is not an ideal to aim for. In the meantime, it’s a comfort to know that smaller projects, like those for Catesby and Ravenel exist.

Crase, D. (2004). Both: A Portrait in Two Parts. New York, NY: Pantheon.

Jarvis, C. (2007). Order Out of Chaos: Linnaean Plant Names and Their Types. London, UK: Linnaean Society.