HEBERLING LAB

This specimen was collected in 1879 by Isaac Martindale, who collected more than 80,000 specimens during his lifetime. The label reads it was collected in "Camden, NJ Ballast."  The specimen was identified as Galingsoga caracasana, which is now considered the same as Galingsoga quadriradiata. The species is native to Mexico, and Central/South America. A common name for the species is "shaggy soldier."  Though my favorite name for the species is "Pittsburgh weed," which it was once called due to its abundance in Pittsburgh.  But that is a different story. 

This specimen was recently used in a fascinating new study published in the American Journal of Botany by botanists by Ryan Schmidt and other botanists at Rutgers University entitled "Hidden cargo: The impact of historical shipping trade on the recent-past and contemporary non-native flora of northeastern United States."  They used herbarium specimens to assemble a dataset of species that were introduced to North America via ship ballast.  In the 1800s, ships travelling across the Atlantic (and elsewhere) filled their hulls with stones, sand, dirt, and other material to use as weight to stabalize the ship.  When then got to their destination port, they dump this extra ballast.  This ballast material often contains plant material, including seeds, thereby making ballast an important vector for the introduction of new plant species from far away.  The study of "ballast flora" has long fascinated botanists, who noticed unusual new plants growing around port cities.  Many of the species may not become established but other species would establish, spread, and become invasive.

There are a lot of fascinating things about this study.  They surveyed specimens in the Mid Atlantic and Northeastern US, many of which were recently digitized through the NSF funded Mid Atlantic Megalopolis Project (including Carnegie Museum!). Based on the labels, they assembled a dataset of species which were introduced or found in "ballast." The study used specimens to track introduction, establishment, and invasion of plants introduced via ballast in New Jersey.

Incredibly, they found that 48% of introductions from ballast became established to some degree! This rate is MUCH higher than what is sometimes suggested (the "tens rule" or 10% of introduced plants become established).  

This study points to herbarium specimens as a unique source of data.  It is very difficult to measure the success of introduced species, as those species that fail to establish are rarely recorded.  

Read more about this cool study here: ​https://botany.one/2023/08/the-hidden-cargo-that-brought-hundreds-of-plant-species-to-the-garden-state/ 

This specimen of white trillium (Trillium grandiflorum) was collected by Fred Utech in Loyalhanna Township, Pennsylvania on May 28, 1993.  Fred Utech was Curator of Botany at Carnegie Museum of Natural History from 1976-1999. You can find this specimen here and search for many more trillium at midatlanticherbaria.org.

Trillium grandiflorum (white large-flowered trillium) is perhaps the most common trillium species in western Pennsylvania, along with Trillium erectum (red trillium, though petals can be white, red/purple, or occasionally yellow; the ovary is deep red, unlike white trillium).  Peak blooms of this species can be breathtaking when covering hillsides. Deer also enjoy trillium, and herbarium specimens have been used to understand their impact.

​As the heat of summer is upon us, these spring blooming species begin to fade. Or at least their flowers do.  Some trillum keep their leaves into the deep shade of summer. Though light levels are low due to the shade of overstory trees, early summer is an important time for many spring blooming species to develop their fruits.  A local study from our group found more than 20% of photosynthetic energy gains in Trillium grandiflorum after overstory trees produced leaves.

White trillium leaves do die back in mid-summer, however.  We often think of leaf coloration in the fall, but some trillium curiously have leaves that turn a deep red as they fade in mid-summer.  We are currently working up an undergraduate students led project on this intriguing natural history phenomenon. Only about 10% of plants turn red (but highly variable), and first results suggest there doesn't seem to be a method to the madness that explains why. More soon!  For now, enjoy the "fall" foliage of summer below.

This specimen of Kudzu (Pueraria montana var. lobata) was collected on October 28, 1920 by Neil MCCallum at West End Park, Pittsburgh.  The plant was collected in cultivation, meaning it was intentionally planted and grown in a garden or similar. This specimen is one of the earliest records of the species in Pittsburgh (It was also collected two years before).

Kudzu is a vine in the bean family, Fabaceae, with beautiful purple flowers. Native to East Asia, it was introduced as an ornamental  the United States from from Japan in 1876 at the Philadelphia Centennial Exposition.  It was promoted in the 1930-40s in the southern US to prevent soil erosion.  However, it is now an invasive species, with big ecological impacts.  It is widely known as "the vine that ate the South."  A quick google search will show you striking pictures of the vine covering large areas of land, covering trees, shrubs, logs, and everything.  It shades out existing vegetation and can drastically alter the ecosystem.

It is not common in Pennsylvania, but perhaps might become so.  It is listed by the state as a "Class A Noxious Weed" - meaning it is assessed as a high invasive risk and ecological/economical concern, but is uncommon and possible to be eradicated.  It can not be sold or planted commercially in PA.

It is currently most invasive in the South, but a study published in 2009 by Dr. Bethany Bradley and others suggests that the species may become more invasive in the north (including Pennsylvania) as climate change continues.

You can find this specimen online here, and search our collection at midatlanticherbaria.org.

Kudzu (Pueria montana) growing along the Kiskiminetas River in Apollo, Pennsylvania in 2018.  It was likely planted, but seems to be doing quite well.

It's spring in Pennsylvania!  And what better sign of spring than trilliums that blanket our forest floors. (Well, in sites that aren't ravaged by deer and other disturbances)

This specimen of great white trillium (Trillium grandiflorum) was collected by Fred Utech on April 1 1997 in North Huntington Township, PA.  The collector number is 97-001, which I think means it was the first specimen Utech collected that year. [Note that every collector has their own system for the collector number - the number after their name on the label. The collector number is a unique number assigned by the collector, and often corresponding to their field notes.  Most collectors number their specimens sequentially but others have other number systems. Here, Utech seems to use the two digit year followed by sequence of numbers for that year. Collector numbers are important, both for the collector to keep track of collections as they press them and make labels but also for researchers later as a unique number to cite or reference in publications or other research.]

Note that the original label says "Trillium nivale" (snow trillium) but another label was added above, a small slip that says "Trillium grandiflorum, det: B.L. Isaac 2004"  This annotation slip means that Bonnie Isaac, Collection Manager at CM herbarium, noticed this specimen was mislabeled and corrected it.  But note the old label remains...keeping the history of determinations for the specimen is important, as it migth be useful for others and perhaps the annotation slip is wrong or as new information arises, our understanding of what species exist changes too! That's why the physical specimen is so important...species names may change, but the specimen remains for verification of new names as we learn more about biodiversity.  This specimen even says "DNA voucher" on the label...and if we didn't have the specimen, we wouldn't be able to update the DNA data.

Trillium grandiflorum (called white trillium or large flowered trillium) is perhaps the most abundant trilliums in western Pennsyvlania.  And they are beautiful.  Peak flower display around Mother's Day.

Leaves gone, but fruits hang on.
 
This specimen of bittersweet (Solanum dulcamara) was collected by Bayard Long on January 11, 1951 in a “rubbish dump” on West Chester Pike, near Broomall, Pennsylvania (outside of Philadelphia).  Bayard Long (1885-1969) was a Philadelphia-area botanist and an active member of the Philadelphia Botanical Club (founded in 1891 and still exists today).  He was a prolific collector and served as Curator of the Club’s Local Herbarium for 56 years (housed at the Academy of Natural Sciences).
 
Bittersweet nightshade (Solanum dulcamara) is in an herbaceous vine in the potato or nightshade family (Solanaceae), not to be confused with the similarly named Asian bittersweet (Celastrus orbiculatus), which is an introduced woody vine in the staff vine or bittersweet family (Celastraceae).
 
Bittersweet is an invasive species, introduced from its native range in Europe and Asia as early as the 1800s. It is common to see climbing along fences in urban areas and elsewhere across North America.
 
In the winter, its fleshy red berries are commonly still attached to the vines, long after the leaves are gone.
 
Find this specimen: https://midatlanticherbaria.org/portal/collections/individual/index.php?occid=12324234
 

Nothing but sticks!
 
This specimen of flowering dogwood (Cornus florida) doesn’t have any flowers...or leaves!  This specimen of dormant twigs was collected by J.F. Lewis in Union county, Pennsylvania on Christmas Eve, 1934.  This specimen is one of many more like in the Carnegie Museum herbarium collected by Lewis of trees and shrubs in Pennsylvania during winter.  The herbarium at California University of Pennsylvania is named after Lewis (John Franklin Lewis herbarium). It is not immediately clear from the specimens themselves why Lewis collected these, but they likely document a study on winter twigs or to aid the identification of trees in winter.
 
Find this leafless specimen and 240 more collected by J.F. Lewis here: https://midatlanticherbaria.org/portal/collections/list.php?db=328&collector=Lewis%3B+J.F.&includecult=1

Though the supercontinent Pangea broke apart many millions of years ago, the Anthropocene is marked by a new kind of Pangea. Though the seven continents as they are today may not be physically connected into a single landmass, they are perhaps more connected than they have ever been. The globalization of human activities has brought species from around the world into contact which otherwise would never interact. Some species are intentionally moved from one continent to another, such as the plants in gardens, while other introductions are accidental, mere unintentional passengers of human increasingly global activities. Introduced species can fundamentally alter the landscape and are regarded as one of the top threats to native biodiversity.
 
Invasive species are those introduced species which are non-native and spread without human intervention.  Many invasive species alter ecosystem functioning and change regional biodiversity. Invasive plant species have become a common part of our landscape. Some were brought over hundreds of years ago by European colonists. Others have arrived much more recently.
 
In Pennsylvania, the invasion of some plant species are obvious – that is, a unique species arrives, thrives, and become abundant. These invasive species have no record of being in the area and can spread rapidly, sometimes over the course of a human lifetime or shorter. Many invasive species are still actively spreading across the landscape. For instance, garlic mustard (Alliaria petiolata) is a well-known forest herb from Europe introduced to North America in the mid-1800s and after more than a century are now common across Pennsylvania forest. Another obvious example is giant knotweed (Reynoutria sachalinensis), a native to parts of East Asia, first recorded in western Pennsylvania in the 1920s and has since spread to line many of Pennsylvania’s rivers and streams today. You can’t go far in the Pittsburgh region without seeing invasive knotweed.
 
Other species invasions are less obvious. These so called “cryptic invasions” are the introductions of very closely related species or subspecies which originated elsewhere.
 
This specimen of common reed (Phragmites australis) tells the tale of a widespread cryptic invasion. The specimen was collected by Carnegie Museum botany curator Otto Jennings on November 2, 1930 along the shores of Lake Erie at Presque Isle, Pennsylvania. Common reed is a major problematic invasive species, crowding out native species in this unique habitat at Presque Isle. When this specimen was collected over 90 years ago, it was not nearly as abundant as it is now.
 
But is it non-native? Common reed, or often simply called Phragmites, has a very widespread distribution, found in wetlands and shores across all continents except Antarctica. It is even not an uncommon site along wet areas near highways. It is among the most widely distributed plants in the world.
 
Reed is non-native to the United States...well, mostly. In the 1800s, botanists considers Phragmites to be a relatively uncommon plant. Evidence from fossils and paleocological research show that the species has indeed been in North America for many thousands of years. However, it didn’t start to become abundant until the early 1900s and after. Some botanists suggested the sudden success of the species could be due to human disturbance.  A pioneering herbarium-based study 2002 published in the PNAS by Dr. Kristin Saltonstall sequenced DNA from herbarium specimens collected before 1910 and recent collections to show that the spread of Phragmites in the United States was due to the introduction of a non-native strain of the species that originated from Europe.
 
Pretty cool, huh? And this finding was made possible with herbarium specimens.
 
So, is this particular specimen native or not?  I don’t actually know, but with expert examination and genetic analysis, we could find out!
 
Find this specimen and 149 more in the Carnegie Museum herbarium here: https://midatlanticherbaria.org/portal/collections/list.php?db=328&taxa=Phragmites+australis&usethes=1&taxontype=2

A large stand of Phragmites at Presque Isle State Park, Pennsylvania (August 2019).

Bright fall foliage of deciduous trees gets a lot of attention in autumn...and rightfully so!  But fall is also a time when those minority of plants that don't drop their leaves also become more prominent. 

This evergreen specimen of great rhododendron (Rhododendron maximum) was collected by John A. Shafer in "Schenley Homestead" in Pittsburgh  in October 1883.  The fruits on the specimen are a reminder  of the big blooms from the summer.

This specimen was collected in Schenley Park before it was a park! Pittsburgh's second largest and much beloved city  park came to be after the donation of the large tract of woods by Mary Schenley on October 30, 1889 -- six years after this specimen was collected.

Just adjacent to the new Schenley Park, Carnegie Museum of Natural History opened its doors several years later in 1895, where this specimen would eventually end up.  Before that, the specimen was a part of the herbarium of the Botanical Society of Western PA, which would later become the Carnegie Museum herbarium.
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Botanical look-alikes...on the other side of the world!
East Asia-Eastern North America are more similar than you might think.
 
This maple specimen was collected in August 1937 by J.R. Steck and R.J. Templeton in Pittsburgh’s Schenley Park. At first look, it is clearly a maple...its leaves have that “mapley” look!  But upon closer inspection, this specimen was collected from a planting. The species is from Japan – Honshū maple or grey-budded snake-bark maple (Acer rufinerve).

Now, check out this doppelgänger specimen, another maple collected by famed Carnegie Museum curator Otto Jennings in late August 1925 in Elk County, Pennsylvania. This similar looking species is found across Eastern North American forests – striped maple (Acer pensylvanicum).  Though you can’t tell from these leaves and stems, the bark also has distinctive striping (hence the name) that is uncannily like its Asian relative species above.
 
There are many species across Eastern North America and far away East Asia that look almost identical at first glance.  Why?  This observation has long been of interest to botanists for centuries, notably by Asa Gray at Harvard in the 1800s. Eastern North America and East Asia are comprised of many shared genera across continents, with species within remarkably similar!  These are called “disjunct” genera, resulting from a shared evolutionary history, with both floras once connected in geological time but have since been separated over many thousands of years. Interestingly, of the shared genera between regions, East Asia comprised roughly two times the number of species within compared to Eastern North America.  A lot of interesting evolutionary studies have been done on this disjunction across these floras, with many more to do!
 
Find these maple specimens and 3,030 more from across the world in the Carnegie Museum Herbarium here: https://midatlanticherbaria.org/portal/collections/list.php?db=328&includecult=1&taxa=Acer&usethes=1&taxontype=2
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A flower with no leaves?
 
This leafless specimen was collected in July 1925 in Rock Run, Forbes State Forest in Rector, Pennsylvania.  This site is not far from what would only a few decades later became Powdermill Nature Reserve, the field station of Carnegie Museum of Natural History. 
 
This specimen was collected by Otto Jennings, an influential botanist and curator at Carnegie Museum.  Jennings had many roles during his 60 years at the museum (1904 until his death in 1964), including Director of Education and even Director of the museum.  He was also a university professor at the University of Pittsburgh, serving as the Head of the Department of Botany and later, the Head of the newly formed Department of Biological Sciences in 1935.  On top of that, Jennings somehow was a prolific plant collector, among the top contributors to the Carnegie Museum Herbarium with nearly 35,000 specimens and more distributed in collections across the world.
 
So, where’d the leaves go on this specimen? No, it isn’t parasitic. Wild leeks (also called ramps), Allium tricoccum, has a unique phenology, or timing, of leaf out and flowering. The species emerges very early in the spring, among the earliest in our woods. In this way, the species is a typical “spring ephemeral.” The long leaves soak up the sun before being shaded out by tree canopies a month or two later.  At that point, the leaves dies back.  However, unlike other spring ephemerals, wild leek does not flower in the spring.  Instead, months later, in July, the leafless plants send up a solitary flowering stalk.  This is quite unusual – a flower coming out of the ground in the middle of the woods, with no signs of leaves.
 
Wild leeks or ramps are in the onion family (Amaryllidaceae, formerly Alliaceae), forming bulbs with a distinctive onion flavor and ball shaped flower heads typical in the onion family. Ramps are edible, with a long history of human use by native people and European settlers. Ramp festivals are common throughout Appalachia to this day. However, the species is prone to exploitation and overharvesting, so do not harvest without permission and following sustainable practices to not affect the population.
 
The species is often treated as having two varieties: var. tricoccum (wild leek) and var. burdickii (narrow leaved wild leek). It depends who you ask, but more studies are now more clearly showing that this species may in fact be multiple species based on very distinct phenology (timing of flowers) and leaf traits (color, width).  This case highlights the importance of herbarium specimens in documenting our flora and understanding the complexities of biological diversity.
 
Also note the small label added to this particular specimen recording this specimen was used in the taxonomic treatment of the species in the Flora of North America, identified by T.D. Jacobsen who co-authored the treatment. Dr. Jacobsen is the current director of the Hunt Institute for Botanical Documentation at nearby Carnegie Mellon University.
 
Keep an eye out for those leafless flower stalks in the woods!
 
Find this ramps specimen and 174 more in the Carnegie Museum Herbarium here: https://midatlanticherbaria.org/portal/collections/list.php?db=328&taxa=Allium+tricoccum&usethes=1&taxontype=2

Left: The leaves of wild leeks carpeting the forest floor in early spring.
Right: The solitary flower stalks poking through other vegetation in mid-summer.