Botany Blogs

These blogs are written about and by our Section of Botany researchers. The herbarium at the museum which contains approximately 3,000 type specimens--specimens that define an entire plants' species. These type specimens only represent about 0.6 % of the collection.

Mason Heberling, head of the section, regularly shares herbarium specimens that have been "Collected on this day" in history.

March 9, 2020 by wpengine

Collected on this Leap Day in 1984

Unnamed, but not forgotten!

Today, we celebrate the 9^th birthday of this specimen collected 36 years ago.

This specimen was collected on leap day, February 29, 1984 in Brazil by Keiichi Mizoguchi.

Fun fact: In the Carnegie Museum herbarium, there are 85 specimens collected on leap day, collected between 1872 until 1990. That’s a lot of leap years!

Aside from it being collected on leap day, the specimen label might seem even more unique. Where most herbarium specimen labels have the species name, this one is blank. A big blank spot. The collector did not identify this specimen, nor has anyone else in the past 36 years (yet). This is an “indetermined” or unidentified specimen. It is filed in the sunflower family (Asteraceae) based on its flowers, but it is otherwise not identified.

We can’t forget about these unidentified specimens. Especially those collected on leap day!

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 “undetermined” (also called “indet.”) that includes those specimens that have not yet been identified to species. 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 most likely a member of a species already known to science, but an expert has not yet identified this particular specimen. 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 be 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.

Find this specimen here. Check back, maybe it’ll have a species name on it by next leap year!

Check back for more! Botanists at the Carnegie Museum of Natural History share digital specimens from the herbarium on dates they were collected. They are in the midst of a three-year project to digitize nearly 190,000 plant specimens collected in the region, making images and other data publicly available online. This effort is part of the Mid-Atlantic Megalopolis Project (mamdigitization.org), a network of thirteen herbaria spanning the densely populated urban corridor from Washington, D.C. to New York City to achieve a greater understanding of our urban areas, including the unique industrial and environmental history of the greater Pittsburgh region. This project is made possible by the National Science Foundation under grant no. 1801022.

Mason Heberling is Assistant Curator of Botany at the Carnegie Museum of Natural History. Museum employees are encouraged to blog about their unique experiences and knowledge gained from working at the museum.

February 10, 2020 by wpengine

Collected on this Day in 2012: Wintercreeper

This specimen of wintercreeper (Euonymus fortunei) was collected on January 31, 2012 along the Monongahela River in Fayette County, PA by Alison Cusick. Alison Cusick is a current Research Associate in the Section of Botany at the museum. He can be frequently found in the Carnegie Museum herbarium. He has a unique wealth of knowledge on plants, herbaria, botanical history, and more. He authored three books and more than 50 scientific papers on the flora of eastern North America. Before retiring, he was the Chief Botanist for the Ohio Department of Natural Resources. He continues to collect today, and many thousands of his specimens can found at herbaria across the country.

Note the label on this specimen reads “Cusick, A.W. 37174” The number following a collectors name is known as the…you guessed it… collector number (surprise!). The collector number is the number assigned to a specimen by the collector. It is common for several specimens to have the same collector number, if they are from the same individual or species in the same location on the same day (“duplicate specimens”). Unfortunately, there are no universal rules on how collector numbers are used or assigned. Collector numbers primary use is so the collector and/or others using the specimen can go back to the collector’s field notebook for additional information on the specimen. Collector numbers are different from specimen numbers (which are assigned by the herbarium, such that every specimen has a unique ID for reference). Most collectors number their specimens chronologically in order they were collected (but not always), but some collector numbers consist of dashes and/or letters, too.

Anyway, what I’m getting at is that this specimen (Cusick 37174) suggests Alison has collected AT LEAST over 37,000 specimens. The number is actually higher than that, with duplicates and an additional 8 years of collecting. Not that numbers are everything, but Alison’s contribution to the herbarium record is clearly impressive and impactful.

Ok, now back to the plant! Winter creeper (Euonymus fortunei), native to Asia, is commonly planted in Pennsylvania and many other places, and unfortunately has also spread to become invasive. It is still commonly planted. It is a woody vine that climbs trees, but also is a thick ground cover. It has leaves that persist through the winter, with attractive fruits. Despite those advantages, it can impact native species and habitats as an invasive species, and therefore, should not be planted.

Find this specimen and more here: http://midatlanticherbaria.org/portal/collections/individual/index.php?occid=12134036&clid=0

October 18, 2019 by wpengine

The History of Jack-o’-Lanterns + Make Your Own Dippy Jack-o’-Lantern

Did you know jack-o’-lanterns were once carved from turnips? Ancient Celtic cultures were known to carve turnips and place embers inside to ward off evil spirits. That’s because Ireland didn’t have pumpkins. When immigrants brought over their carving tradition, Americans began carving jack-o’-lanterns from pumpkins. This gave us a bigger canvas to work with!

This is a traditional Irish jack-o’-lantern carved from a turnip.

The Great Pumpkin Flood

Can you imagine Halloween season without pumpkins? More than 200 years ago, eastern Pennsylvania experienced heavy rain causing the Susquehanna River to flood. The flood waters were so strong they washed away entire pumpkin crops. People were said to have seen pumpkins floating down the river, which was 5-10 feet higher due to the flooding. When the water began to subside, pumpkins were everywhere. This was known as The Great Pumpkin Flood of 1786.

The Nature360 Staff had a pumpkin carving party. Can you see Dippy riding a broomstick?

Dippy the Dinosaur Jack-o’-Lanterns

Our friend Dippy had so much fun with our last challenge, that they asked us to give you another! Do you think you can carve a Dippy jack-o’-lantern?

We have three pumpkin carving stencils for you to use that will bring Dippy to life, pumpkin style! You can choose to carve Dippy wearing a witch hat, Dippy in the night sky, or Dippy on a broom stick.

We’d love to see your jack-o’-lantern creations! Email them to nature360@carnegiemnh.org or tag Dippy on Twitter @dippy_the_dino.

Dippy in a witch hat jack-o-lantern pattern

Dippy in the night sky jack-o-lantern pattern

Squash Dolls

Although pumpkins didn’t serve a large purpose in home decor until we began carving them, squash was popular to the Hidatsa Indians. Little girls were known to use squash as dolls. They would bring them in from the field, picking the ones that were multicolored, so the dolls looked to be wearing clothing.

Try more fun activities in Nature Lab!

October 15, 2019 by wpengine

Callery Pear from October 11, 1979: 40 years ago

From wild to cultivated to invasive

This specimen of Callery pear (Pyrus calleryana) was collected on October 11, 1979 by W.Z. Fang in Jiangsu, China. Callery pear is native to East Asia (China, Vietnam).

But…Callery pear can be found in the United States. It was (and is) widely planted as an ornamental landscape tree. Along streets, in residential yards, in parking lots – it was a prized plant for well-groomed anthropogenic landscapes. It uniformly grows in low resource conditions, explodes with many beautiful blossoms each spring, provides shade, and has a decent foliage display in the autumn. As many introduced plants go, it went from prized ornamental to an unwanted “invasive species,” spreading across the landscape and affecting the environment. It is now widely recognized invasive species in many states or closely watched as a species likely to become invasive. That said, beyond the legacy of over half a century of mass plantings across the country, it is still commonly planted and old and new cultivars are commercially available. USDA estimated over $23 million in sales in the US in 2009 alone.

How’d Callery pear get to the US? The story behind the introduction of Callery pear is a fascinating one. Like many of our cultivated plants, seeds were collected on special expeditions in search of plants useful to horticulture, agriculture, or just because. Pyrus calleryana was first introduced to the US in the early 1900s, though not for its attractive blossoms as you might expect. Instead, it was first introduced for its disease resistance. It was successfully used in horticulture as a root stock for European pear fruit production. At the time, European pears in the Pacific northwestern US were being hit hard, grafting to a Callery pear rootstock dramatically decreased crop losses to disease. Callery pear does not produce edible fruit.

The tree was widely planted starting in the 1960s, when it became commercially available and promoted by the nursery industry as a hardy ornamental tree. Before that, it was planted by the US Department of Agriculture (USDA) for testing at Plant Introduction Stations in Corvallis, Oregon, and Glenn Dale, Maryland. One of these Maryland planted trees was targeted for its special traits and became the source of the hugely popular ‘Bradford’ cultivar (“Bradford pear”). In 1952, one tree was used to graft to rootstock, a plant propagation method making all plants genetically identical. Other cultivars have since been commercialized, but ‘Bradford’ were/are exceptionally popular. Though intended to be sterile (non-reproducing), it turned out the trees were capable of setting viable seed. The cultivars themselves are not invasive, but because multiple cultivars exist, together they can cross-pollinate to become invasive.

This flowering specimen (above) from University of Maryland Norton-Brown Herbarium (MARY) was collected in 1963 from the US Plant Introduction Garden in Glenn Dale, MD – THE site behind the widespread introduction of this species!

Herbarium specimens have been critical to understanding the spread of this species. In a 2005 study, Dr. Michael Vincent (Miami University in Ohio) found that 50% of all specimens examined over the range of 39 years were collected between 2000-2003. Though some specimens were collected in the 1960s in natural areas, it became widely “escaped” from cultivation in many natural areas in the 1990s.

You may have noticed that most of our specimen images to date are those collected in Pennsylvania and surrounding states. That’s because these specimens are being digitized as part of a multi-institutional project, the Mid-Atlantic Megalopolis Project, with the overarching goal to mobilize herbarium specimens across the region to understand the effects of urbanization on plant life. However, this project is a step towards digitizing the entire Carnegie Museum Herbarium. The herbarium is worldwide in scope, and specimens in the Mid-Atlantic region account for only 35% of the 540,000 specimens.

As more specimens become digitized as part of the Mid-Atlantic Megalopolis Project, we’ll have a more complete understanding of the introduction and spread of Callery pear in the region.

Herbarium specimens are collected in the native range too! We’ll be able to compare specimens collected in the invaded range to those in its native China. The use of cultivated specimens and those collected in the native range are underutilized but can provide critical information.

This historically fascinating specimen (above) from Howard University Herbarium (HUDC) below, digitized through the Mid-Atlantic Megalopolis Project, is among the oldest specimens collected in the region. Collected in spring of 1965 in Maryland by Frederick Meyer from a cultivated plant at the US National Arboretum, with the note on the label: “China: Seeds collected by Peter Liu, Hupeh Province. Rec’d. March 10, 1932.” The US National Arboretum was instrumental in the development and popularity of the ‘Bradford’ and other cultivars.

Escaped from cultivation. This specimen (above) from Muhlenberg College Herbarium (MCA) was collected along the roadway in Montgomery county, Pennsylvania by Bayard Long in 1962. This specimen is probably the earliest specimen collected in the wild in Pennsylvania.

Many more specimens like this will be brought to light through the Mid-Atlantic Megalopolis Project.

Read more about this species introduction history in the popular press, published in the Washington Post last year, and in an excellent overview by Dr. Theresa Culley (University of Cinncinati) in Arnoldia and another in BioScience.

See all the Pyrus calleryana specimens being made available online from the Mid-Atlantic Megalopolis project here: http://midatlanticherbaria.org/portal/collections/list.php?db=277%2C328%2C334%2C329%2C333%2C320%2C330%2C40%2C410%2C316%2C335%2C331%2C332%3B11&includecult=1&taxa=Pyrus+calleryana&usethes=1&taxontype=2

October 15, 2019 by wpengine

Glowing Mushrooms and Pokémon

Nature’s Nightlights

Have you ever walked through the woods at night and noticed a small glowing object near the base of the trees? That’s bioluminescence happening in mushrooms – the creation and emission of light by organisms. Glow-in-the-dark fungi aren’t just something you’ll see in the woods. If you’ve seen the new Detective Pikachu movie, you may have encountered another species of glowing mushrooms!

The radiant glow of bitter oyster mushrooms were used to mark trails prior to electricity!

What We Know About The Glow

By now, you’ve probably got some questions, like how does the glowing occur? And why? Well, the greenish light emitted from the mushrooms is the result of a release of energy from a chemical reaction. Research has shown that when the oxyluciferin in the mushroom releases its oxygen molecule, then it’s time to get lit. Only about 80 species of fungi are known to glow. Perhaps these funny fungi are drawing the attention of insects or animals that feed on the mushroom to disperse its spores, like the way a sweet-smelling flower attracts insects for the same reason.

These mushrooms are as plain as Clark Kent until they give off a super glow at night.

Glowing Mushrooms From Different Worlds

If you’re having trouble finding glowing mushrooms in the woods, have no fear, Detective Pikachu is here! The new movie shows off different types of Pokémon, including the Morelull. The Morelull is a Pokémon that resembles a mushroom with its stem-like body and three sprouting mushroom caps on its head. At night, the Morelull can make its spores glow with glittering sparks just like glowing mushrooms around you.

glowing mushroom-like Pokemon — A Morelull resembling a glowing mushroom appears in the wild during the Detective Pikachu movie trailer.

Fun Fact – Hypnotizing Spores

You can find Morelull in the Detective Pikachu trailer! When the trainers come across a herd of Bulbasaur, look for a few Morelull fluttering around them.

Detective Pikachu screenshot of Morelull

It’s Time For An Adventure!

Now it’s time for you to find glowing mushrooms near you. If you’re stumped on where to find nature’s nightlights, well, look for a stump! They are known to surround the bases of dead trees or wrap themselves around dead branches.

Popular glowing mushrooms:

-Luminescent Panellus

-Honey Mushroom

-Bleeding Fairy Helmet

-Jack-o-Lantern

Western Pennsylvania is home to several varieties. They can be found in backyards, along trails and in our parks such as:

-Powdermill Nature Preserve

-Beechwood Nature Reserve

-Frick Park

-Hartwood Acres

-Salamander Park

While you’re out looking for mushrooms, keep your eyes open for fireflies! Fireflies use luciferins, light emitting compounds, like mushrooms to glow.

glowing mushroom — A Jack-o’-Lantern Mushroom glows under the moonlight at Beechwood Nature Reserve.

The same Jack-o’-Lantern Mushroom in the daylight.

Can You Find The Words Relating to Mushrooms?

Learn more in Nature Lab!

October 4, 2019 by wpengine

October 4, 1940: 79 years ago

Loved and hated: An urban plant with history

”There’s a tree that grows in Brooklyn. Some people call it the Tree of Heaven. No matter where its seed falls, it makes a tree which struggles to reach the sky. It grows in boarded up lots and out of neglected rubbish heaps. It grows up out of cellar gratings. It is the only tree that grows out of cement. It grows lushly…survives without sun, water, and seemingly earth. It would be considered beautiful except that there are too many of it.“

-from Betty Smith’s classic novel, A Tree Grows in Brooklyn (1943)

(Fact check: the species is impressively resilient but does indeed require light and water. But we’ll let it slide with an artistic license here.)

This specimen of tree of heaven (Ailanthus altissima) was collected on October 4, 1940 by D. Berkheimer near Klapperthal in Berks county, Pennsylvania.

Tree of heaven (Ailanthus altissima) is a species with a fascinating and complex cultural history. It was once glorified as a beautiful urban street tree in the United States. It was tolerant of insects, pollution, and poor growing conditions. The earliest recorded planting in the US (via England) was at William Hamilton’s estate (currently the “Woodlands Cemetery”) in Philadelphia around 1784. It was also in Bartram’s famous garden nearby. It became popular in the plant nursery industry after 1820. But that feeling didn’t stay long, and within decades it was vilified as an unwanted weed – it had an unpleasant smell, produced prolific seeds, and resprouted from suckers causing it to spread. Today, it is a common urban “weed” found in urban and non-urban areas across the eastern US. It is considered invasive in Pennsylvania (and many other states). It is also considered invasive in many parts of Europe.

But where’s it from? Ailanthus altissima is native to East Asia, including China, Taiwan, and Korea. It has a deep ethnobotanical history in China, where it has been used in various ways in traditional Chinese medicine, with written records of its use dating to 732 AD! It also has deep roots in Chinese literature and culture. Among other uses, it has also been used in silk production, as it is a food host to a silkworm.

The oldest herbarium specimen from the Eastern US is undated but inferred to date from 1815-1831 from Philadelphia. It is in the herbarium of the Academy of Natural Sciences of Drexel University (PH). The second oldest Pennsylvania specimen is dated 1841, also from Philadelphia.

It is around this time of year that the abundance of Tree of Heaven in the Pittsburgh area becomes especially obvious, especially along roadsides. With large, compound leaves and found in disturbed, “weedy” areas, Ailanthus can be easily confused with the similar looking native tree, staghorn sumac (Rhus typhina). Staghorn sumac is in a different plant family (poison ivy family, Anacardiaceae), but this confusion goes way back. Linnaeus even described the species as in the same genus as sumac, so don’t feel too bad if you make the same mistake! (Side note – the taxonomic history of the species is also intense. It has been given many different scientific names over the past three centuries, with three people independently naming it at around mid-1700s!) The leaves are noticeably different upon closer inspection. The fruits are even more clearly different. Ailanthus has brown clusters of winged seeds (called samaras, like that of maple trees’ “helicopter” seeds). These seeds can be clearly seen now on trees as their leaves drop along most highways around Pittsburgh.

Given its introduction history in the Mid-Atlantic and its intentional planting and affinity for urban areas, the Mid-Atlantic Megalopolis Project will be important and fascinating to understanding more about this plant. The Mid-Atlantic Megalopolis Project is a specimen digitation effort involving more than 12 herbaria (including Carnegie Museum herbarium) funded by a National Science Foundation grant to database (put in computer), image (high res. pictures), and georeference (put on map) all specimens in the region. The region is significant because it is one the oldest densely populated urban corridors in the US, from New York City to Washington, D.C. The Mid-Atlantic Megalopolis Project is producing a critical dataset to look at the introduction history and invasive success (and failure) of species in urban and non-urban areas across this connected region – including Tree of Heaven and many other species.

This specimen image (and many other Tree of Heaven specimens in the region) are available online: http://midatlanticherbaria.org/portal/collections/list.php?db=328&taxa=Ailanthus+altissima&usethes=1&taxontype=2

The earliest specimen in southwestern PA at the museum was collected in 1881 in Beaver county.

For more on the species’ fascinating history and biology in our region, check out this detailed study by Dr. Matt Kasson and colleagues done at Penn State published in 2013 in Northeastern Naturalist.