Collected on this day...
a weekly blog featuring specimens in the Carnegie Museum's herbarium.
each specimen has an important scientific and cultural story to tell.
each specimen has an important scientific and cultural story to tell.
How do you fit the tallest plant in the world on an herbarium sheet? On January 21, 1904, this California redwood specimen was collected by E. Dudley in Santa Cruz Mountains, California. California redwood or coastal redwood (Sequoia sempervirens) is an evergreen tree, which can possibly live for up to 2,000 years and reach well over 300 feet in height! Discovered in 2006, the tallest individual ever recorded was 379.7 feet tall. The species is native to the United States, found in the iconic redwood forests along the coast of California and into Oregon.
Collected on January 12, 1935, this specimen of American hazelnut was found by John Franklin Lewis on Limestone Hill, near Connellsville, PA. The herbarium at the California University of Pennsylvania is named after John Franklin Lewis. American hazelnut (Corylus Americana) is a native shrub, found in woods across the Eastern US. It is monecious, meaning it has separate male and female flowers on the same plant. The structures at the end of many of the branches in this specimen are immature male flowers (called “catkins”), which remain present through the winter. In spring, these male catkins hanging from their branches will flower to spread pollen in the wind. The hazelnuts are produced from the female flowers. This plant can be an important food for wildlife. The nuts are said to taste similar to cultivated European hazelnuts, but are smaller.
Some species are well adapted for life in the Anthropocene, commonly found in novel, human-made habitats such as roadsides, sidewalk cracks, farm fields, dumps and industrial sites. One such plant species that particularly well suited to city life is “quickweed” (Galinsoga quadriradiata). It has many common names, including “Peruvian daisy,” “shaggy soldier,” and “fringed quickweed.” In fact, the species was once known locally as “Pittsburgh weed.” To our knowledge, this is the only example of a non-native species that was first recorded in North America in Pittsburgh (or at least among the earliest). It was introduced here from South America sometime in the mid-1800s. Pittsburgh weed was first discovered by the courthouse in Pittsburgh by Judge John D. Shafer (1848-1926), a prominent lawyer and dean of Law School of the Western University of Pennsylvania (now University of Pittsburgh). An avid botanist, Shafer was also a founding member of the Western Pennsylvania Botanical Society. The specimen pictured here is one of the earliest (if not the earliest) specimen collected in North America, well outside its native range. It was collected 1869 in along the “Ridge St” railroad tracks in Allegheny City, which has since been annexed by Pittsburgh (now the North Side). Keep a look out for this interesting species throughout the city, especially along sidewalk cracks and at the base of street signs and electric line poles. It is now a common weed, and can be found in nearly every major city all over the world.
Below: Close up of original specimen label from the earliest collection (that still exists) of the species in Pittsburgh, collected in 1869.
Below: "Pittsburgh weed" (aka "quickweed") taken on October 13, 2017 in the lawn near the Carnegie Museum of Natural History.
Even though it was collected in Japan, this specimen might look familiar in Pennsylvania. This specimen of wintercreeper (Euonymus fortunei) was collected by M. Togashi in Japan in 1985. Native to East Asia, wintercreeper (also called Fortune’s spindle or climbing euonymus) was introduced to North America in 1907 for use as a ground cover. In fact, it can be found just outside the Carnegie Museum, around the parking garage. It can escape cultivation, to establish and become naturalized (sometimes invasive) in the Eastern United States. Wintercreeper is a fast-growing woody vine which has evergreen leaves. Wintercreeper is recognized as invasive by the Pennsylvania Department of Conservation and Natural Resources (PA DCNR), with potential to cause ecological harm in natural areas (link).
Herbarium specimens are valuable resources to study invasive species -- not only to monitor changes through time (since introduction) and to track its spread across the US, but also to compare to populations growing in the native range. Much untapped potential in herbaria worldwide for understanding species invasions.
Stumbled upon this neat little book from 100 years ago in the Botany library, which promotes the use of this plant as an ornamental. The book was published in 1917, ten years after wintercreeper was introduced to the US. Many states (including PA) now recognize this species as problematic or having the potential to become invasive. [note: Evonymus radicans is a synonym for Euonymus fortunei var. radicans]
Below: Euonymus this morning outside the museum. Probably not much photosynthesis happening this winter morning, given it is 0 °F (feels like -18°F)!
What plant is this? Well, we don’t know exactly. This undetermined specimen was collected on December 29, 1976 by Jeffrey McElroy in Ecuador. The label suggests it is in the same plant genus as the papaya (Carica) but was not yet identified to species. Specimens in the herbarium are arranged by plant family, then genus, then geography (where it was collected), and in nearly every genus, at the bottom of all these folders is a black colored folder labelled “indet.” that includes those specimens that have not yet been identified to species. I’m not sure why they are called “indet.” rather than “undet.”, as “undetermined” would be more appropriate. Of the over 525,000 specimens in the Carnegie Museum herbarium, about 2% (= 10,588 specimens), are not (yet) identified to species.
This specimen is likely a member of a species already known to science, but an expert has not yet identified this particular specimen yet. However, many undetermined specimens may be undescribed (that is, new to science!). The name and description of new species (alpha taxonomy) is a major purpose of herbaria. A study in 2010 estimated that of the estimated 70,0000 species yet to be described, over HALF are lying in herbaria right now! They also found that only 16% of new species descriptions were done within 5 years of specimen collection, and 25% of new species descriptions involved specimens that were more than 50 years old!
Study abstract here: http://www.pnas.org/content/107/51/22169.abstract
Taxonomy (branch of science on classification of organisms) is always changing. Species names are changed, what was once thought to be one plant species or family is split into many, and what was thought to several species is lumped into one. And with further information or upon review by experts in particular plant groups. specimens are determined to be a different species than what the original collector called it. Annotation labels are added to specimens all the time – these labels revise the species listed on the original label. A typical annotation label includes the revised species name and details, the name of the person making the annotation, and the date.
Some specimens can have many annotations, which nicely demonstrates the community culture of science as a process with constant revision as we learn more about the world around us.
Image above: European mistletoe specimen collected on Christmas Eve, 1883.
Image below: Close up image of specimen label that reads: "a. purchased at Pittsburg market." It took me a while to decipher this handwriting. Note that Pittsburgh's official spelling was "Pittsburg" until 1911. The mistletoe was for sale for the holidays, likely imported from its native range in England.
Well, specimens don’t get much more festive than this! This mistletoe specimen (Viscum album) was purchased at a Pittsburgh market on Christmas Eve 1883 by John A. Shafer, who would become the museum’s first botany curator 16 years later. Mistletoes refer to many species in the genus Viscum, but traditionally referred to a species native to Europe, Viscum album. European mistletoe has a deep rooted cultural history, dating back to as early as ancient Greece, is a part of many legends and stories through human history, and remains a well-known holiday decoration today.
Did you know that mistletoes are parasitic plants? Mistletoes grow on the branches of trees (especially oaks), with specialized roots (called “haustorium”) that penetrate the host tree to obtain water and nutrients. Technically, most mistletoes are hemi-parasites, as they do have green leaves capable of photosynthesizing to some degree. How do they germinate high up on the branches of trees? They have evolved to produce berries which birds ingest, fly around, land on another branch, and poop a viable mistletoe seeds. Without the assistance of birds, the seeds would likely just fall to the ground.
Mistletoes are native to the United States, too. American mistletoe (Phoradendron leucarpum) is native to southeastern US states. The species has been harvested and sold in the US in Christmas traditions, similar to European mistletoe. The specimen pictured below was collected in South Carolina in 1968, found attached to several oak species.
This isn’t your typical herbarium specimen (or is it?). It is a “type” specimen collected by A.H. Curtiss on December 15, 1903 on the Isle of Pines, Cuba. A “type” specimen is a specimen that was used to formally describe the species as new to science. Therefore, type specimens have very special scientific and cultural significance. This species was named Acisanthera glandulifera in 1917 by Carnegie Museum curator of botany, Otto Jennings. Jennings and others went on expeditions to Cuba in the early 1900s, and many specimens are now preserved at the Carnegie Museum.
Type specimens serve as a verifiable record for future researchers to compare and verify a given species’ identity. There are many different categories of types. In particular, this specimen is a “holotype,” meaning it is the sole designated specimen that describes the species. Current rules set forth by the botanical research community are that the species description much be published in a peer reviewed journal and must designate one single specimen as the holotype. Because individuals can vary in their feature, other specimens can be referred to in the species description as well. These specimens would be known as syntypes. Similarly, a specimen which was said to be made from the same exact individual as the holotype is known as the isotype. It is common practice for botanists to send duplicates of the holotype (aka "isotypes") to other museums to be a part of their collection.
Taxonomy (the science of classifying organisms) is an ever-changing science, subject to revision as more research is done, especially at the molecular (DNA) level. What was once thought to be one species might actually be several, and what was thought to be several species might actually be one. In addition to a species being recognized as new, some species simply change their names as a result of new evidence suggesting it should be being placed in a different genus (thereby changing its binomial scientific name). It might seem unnecessary to go to the trouble to name species or have botanists argue over what is a species and what isn’t. But taxonomy is very important for both our basic understanding of the tree of life, but also for biodiversity conservation. If we don’t know what species are out there, we won’t be able to effectively conserve the world’s biodiversity. After all, it is tough to protect a species you didn’t know it exists.
Another major reason for changes in species names is more due to nomenclature rules and dealing with synonyms. A species may be independently described multiple times and many species have a complex nomenclatural history (that is, they have been called multiple scientific names by different people). Assigning one accepted scientific name to a species helps to ensure that scientists working on the same species are indeed referring to it as the same species.
You’ll notice many herbarium specimen labels have additional labels (annotation labels) to update the specimen’s identity as new information becomes known. An annotation label can be seen in this specimen pictured here (specimen was first labelled as a different species name). In fact, a recently published treatment of this genus (Guimaraes et al. 2017, Brittonia) suggests this species name should be Acisanthera erecta.
Although this specimen isn’t your average specimen, can you say it is a “typical” specimen? [insert laugh here]
Above/below: The original 1917 publication by Jennings describing this species.
Below: Many type specimens are now available online (CM’s specimens are currently available on https://plants.jstor.org/ ). Pictured here are duplicate specimens of the holotype (isotypes) in other herbaria. Below is one specimen from the New York Botanical Garden (NY) and another from the United States National Herbarium at the Smithsonian (US). I was able to find these duplicate specimens in a matter of minutes --thanks to recent digitization efforts!
Fa la la la la, la la la la
'Tis the season to be jolly.
Are you decking your halls with boughs of holly? This specimen of American holly (Ilex opaca) was collected by M.L. Bomhard in Mandeville, Louisiana by on December 8, 1928. The holly revered for its holiday cheer usually refers to a related European species, Ilex aquifolium. But there are native holly species in North America that are equally (if not more) cheerful. Like most other hollies, American holly is dioecious, meaning it has male and female flowers on separate plants. Only the female plants have the characteristic bright red berries we all know and love. American holly stands out as one of the few broadleaved evergreen trees native to the Eastern US (i.e., has green leaves during winter that are not needles). This species is near the northern edge of its range in Pennsylvania and is more common in southern states. It is listed in PA as a species of “special concern” due to its relative rarity.
Indiana, PA: Christmas Tree Capital of the World!
Around 25-30 million cut trees are sold each year in the United States for the holidays.
These Pennsylvania specimens shown above were collected sometime in December (exact day unknown): White Pine (Pinus strobus) in Kittanning in 1926 and Scots Pine (or “Scotch Pine”; Pinus sylvestris) from cultivation in Avalon in 1902. Both of these species are cultivated and used as decorative trees for the holidays. Many evergreen conifer species are cultivated in the US for decorative use during the holidays. Needle length, softness, retention, color, and even scent vary by species or variety. Similarly, branching patterns and branch strength differs. Plus, some species grow faster and easier than others, which means some species are cheaper.
Did you know that Pennsylvania is one of the top states for Christmas tree farms? In fact, southwestern PA’s very own Indiana County is known as the “Christmas Tree Capital of the World.” According to the Indiana County Christmas Tree Growers’ Association, the title arose in 1956, when an estimated 700,000 trees were cut that year in the county.
Believe it or not, there are no CM specimens from Indiana County collected in the month of December. This isn't all that surprising, as most specimens aren't collected in the winter.
Before farms began cultivating trees for that purpose in the early 20th century, people just went to the woods to cut down their tree for the holidays. Some of the earliest Christmas tree farms in the US started in Indiana County as early as 1918. Many farms in the region turned their fields into Christmas tree farms as it became profitable. By 1960, more than 1 million trees were harvested per year in Indiana County alone. The harvest in Pennsylvania has declined for several reasons, including increased popularity of artificial trees and consumer interest in Frasier fir trees (Abies fraseri; native to the Southern Appalachians and grows slower in PA than farms in North Carolina). However, Pennsylvania is still among the top five states in terms of both number of working Christmas tree farms and trees harvested. According to the National Christmas Tree Association, 31,577 acres in Pennsylvania are used as Christmas tree plantations. Many of the Christmas tree lots in southwestern PA get their trees from farms in Indiana county.
What you know as yams are most likely not really yams. In fact, your “classic” potatoes, sweet potatoes, and yams are all in different plant families. However, they all are widely cultivated for their nutritious starchy belowground plant structures called “tubers.” Tubers function as storage organs for the plants, providing energy for regrowth (the “eyes” or sprouting buds of your potatoes when they sit in your kitchen for too long). Potatoes and yams technically have modified belowground stems (“stem tubers”) while sweet potatoes have “root tubers.”
Yam is a common name for several vine species in the genus Dioscorea (plant family: Dioscoreaceae). They are monocots (related to grasses and lilies). Yams are widely cultivated worldwide, especially in West Africa, where 95% of the crop is harvested. Yams can be stored for very long periods of time, making them an important crop for seasons when food is in short supply. Yam tubers can be as large as five feet long!
Sweet potatoes refer to a vine species (Ipomoea batatas) in the morning glory family (Convolvulaceae). This species is likely what is on your Thanksgiving dinner table. In the United States and Canada, sweet potatoes are often (confusingly) referred to as “yams.” But sweet potatoes are not even closely related to yams. As such, the USDA requires any label with “yam” to also include “sweet potato.” So why are sweet potatoes sometimes confusingly called yams?! Well, this naming probably dates back to colonial times when slaves from Africa noted the similarities between some varieties of sweet potatoes to yams in Africa.
And last - the “classic” potato, Solanum tuberosum. Potatoes belong to the nightshade family (Solanaceace), which also includes many other important crops like peppers, tomatoes, tomatillos, eggplant, tobacco, and more. Critical to the world’s food supply, potatoes are the fourth most farmed crop. Potatoes are only distantly related to sweet potatoes. They are also called “spuds,” which probably originated centuries ago from a term for a spade used to dig holes to plant potatoes. Having been cultivated for centuries, there are thousands of potato varieties worldwide. The cultivated species was domesticated from wild relative potato species in South America (Peru) 7,000 – 10,000 years ago. Important discoveries on the origin of potatoes were based on DNA from 200 year old herbarium specimens! Similarly, the origin of the Irish Potato Famine (caused by potato late blight from a fungal pathogen) was also discovered using fungal DNA extracted from 160+ year old herbarium specimens!
For more on cool new Irish potato famine research: http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0168381
For more on origins of European potato: https://www.ncbi.nlm.nih.gov/pubmed/21632349
Specimen above: "Yam" species (Dioscorea schimperiana) collected in 1960 by A.C. Twomey in Kenya. Yams are an important food crop across Africa.
Specimen below: "Sweet potato" (Ipomoea batatas 'Georgia Jet') collected in 2001 by Bonnie and Joe Isaac in a garden in Pennsylvania.
Specimen below: Your "classic" potato (Solanum tuberosum) collected in 1982 from a farm in Peru. Research suggests Peru to be the site of early domestication over 7,000 years ago.