- Massey JR. 1974. Chapter 31: The herbarium. In Radford AE, Dickison WC, Massey JR, Bell CR. Vascular Plant Systematics. Harper and Row Publishers. Retrieved from http://herbarium.unc.edu/chpt31.html
When you first learn about stacks of plant specimens housed in herbaria, it is tempting to envision these collections as quiet, inanimate storage spaces. You can imagine the smells of paper and dust, the quiet hum of florescent lights, and imposing rows of tightly shut cabinets. Indeed, many California herbaria are currently fated to this state with the shelter-at-home order still in place, but this was not always the case. Herbaria can be bustling hubs of creating, tending, discovering, and learning, and without constant care and curation, years of hard-earned data can be imperiled. Even when students learn from home and researchers keep to their desks, herbaria still require resources and attention.
Herbarium specimens are like delicate archival books: subject to rot, insect infestation, and general decay when not properly cared for. This is particularly important in warm environments, where heat and humidity can accelerate deterioration, the growth of mold, and the proliferation of pests. In California, one such infamous pest is the cigarette beetle, a tiny but destructive creature that can consume all plant matter on an herbarium specimen (and leave holes in the mounting paper, to boot!). Book lice are even smaller pests—about the size of a grain of sand—that nevertheless have huge appetites and can munch through herbarium specimens at startling speed. Flowers and fruits, perhaps the most important features for conclusively identifying most plant species, are often the first parts to be targeted.
Controlling pests is a continuous battle. Historically, curators and collections managers used pesticides, but since these substances are often toxic to humans as well as pests, modern managers typically rely on integrated pest management: maintaining an environment that prevent pests and controlling outbreaks by freezing infected specimens. While safer, this approach takes a lot of work. The environmental conditions of the herbarium must be monitored for appropriate temperature and humidity, and cabinets must be constantly checked for new infestations. Once an outbreak is discovered, the cabinet must be sanitized and its entire contents frozen for several weeks. Without regular and careful observation, major and irreversible damage can occur in a relatively short amount of time.
Herbarium curation also includes repairing damaged specimens, organizing specimens that were pulled for research or other use, and—in most collections—keeping up with the backlog of specimens that have been deposited in the herbarium over time. (The latter task can be surprisingly formidable; large herbaria may have full-time staff whose sole responsibility is to mount specimens!) In addition, when not sheltering-at-home, herbarium staff lead tours of students and naturalist groups, and they help researchers, land managers, and the public find the botanical resources they need. All in the day's work for a curator of one of the world's most important sources of botanical data.
Don't let the tall, steel doors and stacks of papers fool you; herbaria are active spaces that need constant, careful support to preserve the irreplaceable data held within. These institutions safeguard centuries of botanical knowledge and hold the keys to countless future discoveries.
While many herbarium collections across the state are sitting in silence, their curators, data managers, technicians, and volunteers are doing quite the opposite. Herbarium databases are a flurry of activity as faculty, staff, and citizen scientists take advantage of the past years of digitization efforts to create and expand herbarium specimen data. Thousands of the >560,000 specimens imaged by the California Phenology Network since January 2019 still need to have their label data entered in the database. These and many thousands more still need to be georeferenced—assigned latitude and longitude coordinates from the location data on the label. Each of these tasks can be done remotely, thanks to the California Phenology Network's online database (CCH2.org) and citizen science platforms like Notes from Nature.
Volunteers have especially showed up during these difficult times—a true testament to the passion and determination of hundreds of citizen scientists across the globe. (A few extra hours to spare can't hurt, too!) The graph below shows the daily number of transcriptions (specimens that have had their label data entered) on Notes from Nature since mid-February. Since the beginning of the shelter-at-home order in California (red line), transcription numbers have shot up and now remain consistently higher than before.
Students and staff who previously spent hours imaging specimens now find themselves at the computer, learning to transcribe label data and georeference specimen records. Weekly "Zoom office hours" bring these dedicated workers together from across the state to check in, ask and answer questions, and build synergy. In the words of the project manager: "We may be isolated, but we're not alone."
As California begins the long road to re-opening, on-site digitization activities at herbaria will slowly resume at a currently unknown rate. One thing is for sure: the herbarium community and plant enthusiasts are certainly not putting their time to waste.
To learn more about getting involved in at-home digitization activities, contact the CAP project manager, Katie Pearson.
Notes from Nature volunteers may not have known it at the time, but while they transcribed the label of this small and unassuming plant specimen, they were documenting the occurrence of a rare, threatened species.
Phacelia mustelina, comically called "weasel phacelia" or more elegantly "Death Valley round-leaved phacelia" is an uncommon annual herb of eastern California and western Nevada. The California Native Plant Society ranks this species as rare, threatened, and endangered in California and elsewhere, and indeed, in our database (CCH2.org), only 39 herbarium specimens exist from the past 100+ years.
This newly rediscovered specimen tells us an interesting story about this unique species. Originating from 1972 in Nye county, Nevada, this specimen was collected as part of a botanical inventory of the Nevada Test Site, an outdoor laboratory for nuclear testing that was established by the U.S. Atomic Energy Commission soon after World War II. Many specimens from this inventory ended up at the CSU Long Beach Herbarium, where they remained undigitized and thus largely unknown for several decades. With recent digitization efforts from the California Phenology Network, however, these specimens were imaged and included in one of our latest expeditions on Notes from Nature.
By transcribing information from specimen labels, citizen scientists helped us rediscover this historical occurrence of the rare Phacelia mustelina. These data are critical for assessing the conservation status of this species; if we know where this plant grew historically, we can better know where it might likely still exist. Once we know where and how abundantly this species exists, we can determine whether it needs protection and how to effectively do so.
If you ever wonder whether your help matters, remember the weasel phacelia. Bringing "dark data" to light can us help protect biodiversity on Earth.
Note: Although the image above doesn't show it, documentation of this species in Nevada does exist in other data portals, so this collection at the CSU Long Beach herbarium does not necessarily represent a range extension of the species.
While working with a batch of specimens, analyzing the contents of their "notes" fields, I came across this strikingly poignant note on a specimen label: "strong aroma reminds me of deer hunting with dad near Lake Berryessa."
The tarweed represented by the specimen sheet is nothing particularly spectacular: a handful of cream-colored flowers, likely a little brown and shriveled due to age, on a spindly stem with thin leaves and minute hairs. The data offered by the specimen--date, location, species--are surely worthwhile for studying plant distributions, ecology, and evolution. Yet something about this quick note reminds us that plants can be even more than data points or scientific curiosities. To humans, plants can evoke memories, symbolize ideas, and encapsulate emotions,
Plants have been used as artistic symbols for centuries in art, literature, and everyday life, from giving a bouquet of roses to a lover, to commissioning a painting of yourself with a pineapple to symbolize how extravagantly wealthy you are (yes, that happened; take a look at this painting of Charles II from 1675).
Different plants are used to symbolize an enormous breadth of human emotion and experience. Oaks can represent strength and royalty (one composer called the oak "England's Tree of Liberty"); daisies can symbolize youth and innocence; in China, the plum represents longevity. Artistically and culturally, plants can remind us certain facets of our existence. Take, for example, these lines of a poem by William Wordsworth, reflecting on daffodils as symbols of joy and rebirth:
"I Wandered Lonely as a Cloud"
On a very personal level, the sight, smell, and even sound of plants can bring us back to pleasant days, like the tarweed collector remembered time spent with a loved one. On a walk or looking out a window, during turmoil, plants can remind us that life goes on, that nature has a way of pressing onward, and that we are all somehow connected to one another in this diverse and dynamic world.
Herbaria are far from static collections of dead plants; with the ongoing activity of botanists, curators, and volunteers, herbaria can be dynamic archives of plant life in this era of rapid anthropogenic change. One such significant change documented by herbarium specimens is the introduction of exotic and potentially invasive species--like the newly documented orchid that may have traveled across the U.S. from Florida all the way to California!
But before we talk about invading orchids, let's get one thing straight: how can herbarium specimens document change?
First, herbarium specimens are used to study how non-native plant species have historically invaded novel regions, as well as what characteristics can make a plant invasive and potentially detrimental to native ecosystems. For example, scientists at Butler and Auburn Universities used herbarium specimens to learn that some invasive species in Indiana got loose by escaping from cultivation (Dolan et al. 2011). Another study found evidence that some species that reproduce sexually may be more invasive than plants that primarily reproduce asexually (Lambrinos 2001). Researchers can look at where and when non-native species were collected and determine whether there are predictable patterns in the data.
So, where does the non-native orchid come in? The story is similar to David Keil's cancerwort discovery, but with even more observers. Earlier this month, members of the Orange County Chapter of the California Native Plant Society noticed a strange new plant growing in a road median in Long Beach.
Botanists took to the investigation. They collected and identified the newcomer as centipede grass orchid (Zeuxine strateumatica), a native of Asia that has become a nuisance in the southeastern U.S. This species had never previously been found in the L.A. Basin and was first collected in the western U.S. only a few years ago in 2017 (Bell & McNeill 2016). Now, we have physical evidence of this plant's introduction into California in the form of carefully preserved herbarium specimens. One of these specimens was collected by one of the California Phenology Network's principal investigators, Amanda Fisher, who also documented the finding on iNaturalist, an app for documenting observations of plants and animals. No photo can substitute for the physical plant itself, however, which will be carefully safeguarded and studied as evidence of our changing world.
References / Further reading
It can be hard to imagine Greater Los Angeles as anything other than the bustling, vibrant, hot, and smoggy metropolis that it currently is. The massive LA metropolitan area is home to some 12.8 million people packed into a sprawling 4,850 square miles dominated by roads, buildings, suburban developments, apartment complexes, and parking lots. But what did it used to look like? Without herbarium specimens, we may have never known.
We may not know in detail what flora and fauna inhabited this lush valley when it was home to Tongva and Chumash tribes prior to the 1550s, but colonial expansion takes time. Western botanists documented plant life in LA basin ecosystems as early as the 1800s, bequeathing us hints of previous ecosystems that are long since buried or past.
Take, for example, this historical specimen of pointed rush (Juncus oxymeris) collected in 1889 by Scottish-American doctor and botanist Anstruther Davidson.
Like many of its kin, pointed rush is a denizen of wetland places (classified as a “facultative wetland” species by the U.S. Fish and Wildlife Service), preferring damp meadows and swales across the western United States (USDA, NCRS 2020; Zika 2015). This is hardly habitat one may associate with LA’s palm trees and oak-lined hills, yet historically, much of the LA basin was wet meadows and marshes (Dark et al. 2011; Grossinger et al. 2011) fed by the ocean and the once free-flowing Los Angeles and San Gabriel Rivers. With urbanization and taming of these once mighty (and often flooding) rivers into concrete channels, alluvial floodplains diminished and wetlands were drained, leaving little habitat for water-dependent species like the pointed rush.
Indeed, there are few reports of pointed rush in the Greater LA area since these early collections. A handful of specimens were collected in the nearby Orange County Saddleback region in the late 1920s to early 1930s, but since then, collections of this species have only been made in the surrounding region, largely in hilly meadows and creeksides far removed from the bustle of the city.
The historical record provided by herbarium specimens is truly irreplaceable. Without these collections, we would have only a dim understanding of the history of life in urbanized areas.
As several herbaria in the CAP network reach their imaging goals, many are beginning to transcribe information from these images into the data portal. (You could help us with this as well...just see our previous blog post!).
One question we hear from many transcribers is: "what are those words after the plant's scientific name?"
The words and (sometimes odd) punctuation after plant scientific names can indeed be confusing, but they provide important information about how the plant is being identified. We call this the species "authorship" or "author citation," and it documents who originally discovered, described, and named this species--or potentially, who re-named the species. In the Ambrosia salsola example above, the author in the parentheses originally named a certain species, but then Strother & B. G. Baldwin gathered more data and determined that this species should be Ambrosia salsola instead of whatever it was previously. This process of determining accurate and useful names for plant taxa is called taxonomy. The words following the scientific names of plant species are the abbreviated names of taxonomists.
Not knowing this, sometimes when transcribers see labels like this, they ask "is this specimen supposed to be gray?"
A. Gray is the standard abbreviation for Asa Gray, one of the most influential American botanists in history. Originally trained in medicine in New York, Gray found that plants were his true passion early in his twenties, and he began what was to become a long and illustrious career in botany. At the age of 28, he was hired as a professor of botany at the University of Michigan, but when funding dwindled, he was appointed as a professor of natural history at Harvard University in 1842, where he worked for over 40 years. Gray traveled to herbarium collections around the world, studying plants that had been collected in North America and naming scores of species. His skill as a botanist was so indispensable that Harvard wouldn't let him retire; it took him several years before he could resign!
Gray authored many foundational works during his career, from textbooks to floras, including the original Flora of North America, which he wrote with longtime colleague John Torrey. Much of what we know about the plants of North America stem from the works of Asa Gray. What better way to remember his contributions than to see his name on thousands of plant specimens?
Many ecosystems—and the diverse plant communities within them—are imperiled in California, raising an important question: what can a concerned citizen do?
No, this isn't a post about donating money, reducing waste, or calling your representatives (all important actions!), we're talking about empowering science, particularly that which examines the effects of anthropogenic change on Earth's biodiversity.
You don't need to be a trained scientist to help advance science. In fact, you can contribute to California botany and change biology from the comfort of your own home using Notes from Nature, a user-friendly website that enables you to view high-resolution images of plant specimens and transcribe data from the specimen labels.
The transcribed data are quality-checked and imported directly into the CCH2 portal (cch2.org), where they are instantly available for education and research, such as studies that examine how a warming climate has impacted plant flowering times, or predict how climate change may affect plant species' spatial distributions. Without these critical data in a digital format (i.e., typed into the computer by volunteers like you), such research is severely impeded.
The California Phenology Network is uploading thousands of herbarium specimen images to Notes from Nature for transcribing, and we need your help to get 'er done!
Did we mention it's super simple to get involved? Here's how you can make a difference:
2. If you want to track your work and earn badges, create an account by clicking REGISTER in the top right
corner of the page.
3. Select a project from the home page. (Pick us, please! You can find the California Phenology Network by looking for the orange poppy).
4. On the project homepage, select an "expedition" from one of the buttons below "Get Started".
5. Read the tutorial for instructions on how to transcribe specimen labels and get started! More help can
be found by clicking the Field Guide tab on the right side of the page, or by clicking any of the links
labeled NEED SOME HELP WITH THIS TASK?
6. Spread the word, be curious, and ask questions! We want to hear what YOU think about these
specimens and the project.
Although he didn't have a GPS handy, Hrusa's description leads us to a fairly specific place on the landscape. The text of the label says "Beach at mouth of San Jose Creek (Monastery Beach) approx. 2 mi. S of Carmel along Hwy. 1. Colony on flat at actual mouth of San Jose Creek." From this information, we can determine the approximate latitude and longitude (with an appropriate approximation of the error of that estimation) of the plant's location. The process of determining geographic coordinates of a specimen from the provided text is called georeferencing.
Georeferencing is an important task. Without georeferenced coordinates, it is difficult to visualize plant collections on a map or create spatial models. The CAP TCN aims to georeference hundreds of thousands of herbarium specimen records using a variety of tools in our data portal (cch2.org). Interested in learning more? Visit our georeferencing page for helpful resources.
Thanks to collectors like Fred Hrusa, we have a better idea of plant distributions over time and space, even on Christmas day.
As you peruse the ever-increasing gallery of herbarium specimens on our portal (cch2.org), you might be struck with an obvious question: how do you mount a dried plant specimen to a sheet of paper? For some plants, the answer seems obvious, but not all plants squish flat in a plant press. What about things like cacti...and whatever this is?
(For the record, this is a Protea, native to South Africa and cultivated in California).
After being collected, pressed, and dried, plant specimens are mounted to sheets of sturdy, acid-free paper using several methods, each with advantages and disadvantages. In early years of herbarium history, the primary method of mounting herbarium specimens was to hand-sew them to the paper. (Yes, that means getting out your needle, linen thread, and a thimble). This method is still used in many herbaria, especially for bulky items like fruits and cones, because of its durability and the fact that it introduces few additional chemicals or adhesives to the specimen. Nevertheless, as you can imagine, sewing is no quick and easy task.
There are other ways that plants have occasionally been mounted in a pinch, including with cellophane tape and plastic wrap, but these do not produce lasting, archival-quality specimens, so they are often re-mounted when they are discovered.
Regardless of the adhesive used, mounting specimens is a blend of science and art. Important structures such as flowers and fruits must be clearly displayed for identification and measurement, leaves must be splayed out to show their full shapes, and there must be room on the specimen for the data-rich label and future annotations. At the same time, well-mounted specimens can embody the life and beauty of the plants they display, and most mounters work hard to produce specimens of high aesthetic quality. Some are more creative than others (see the arrangement of the aquatic plant shown below!), but all resulting specimens are vital snapshots of plant diversity in space and time.
For more information about how plant specimens are mounted, see these resources:
This blog is curated by the project manager of the California Phenology Network, Katie Pearson.