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.
This specimen was collected near Compton's Mills (near Salisbury, PA in Somerset Co.) in 1952. It is a type specimen, meaning it was specifically cited in the publication that formally described this species as new to science. There was quite a bit of confusion regarding naming rules and ambiguities in the original publication, so this location is not technically the type locality. BUT it is certainly a botanically valuable specimen and site. It is a syntype... aka not THE specimen (holotype), but a specimen specifically mentioned in original publication.
This week, we revisited Compton's Mills, on the same calendar day as this specimen was collected. Along with Bonnie Isaac and others at the museum, we are revisiting sites that we have historic collections and recollecting specimens. We plan to compare old and new specimens to compare flowering phenology (e.g., is a species that was in full bloom on May 24 1952, now in fruit on the same calendar day 65 years later?), as well as other aspects of plant population and community changes at a particular site. More soon on this project!
Collected in “late May,” 1923, this specimen was found by in by E.H. McClelland at Idlewild Park, near Ligonier, PA. This herbarium sheet actually contains two different phlox species, Phlox stolonifera (creeping phlox) and Phlox divaricata (wild blue phlox). There are at least seven species of phlox native to Pennsylvania. Phlox is a popular choice among wildflower gardeners. Phlox can be easily confused with Dame’s rocket (Hesperis matronalis), a non-native plant in the mustard family common along many wooded streams and roadsides. An easy way to tell the difference is by the flowers: wild phlox have 5 petals while Dame’s rocket has 4 petals.
Wonder if this species still exists at Idlewild? I'll have to check it out.
Although not the norm, some specimens do not give an exact date, sometimes not even a month, and in rare cases simply give a range of years it was probably collected. Not ideal but these specimens are usually quite old and still important.
Collected on May 19, 2006, this specimen was found by Loree Speedy in a stream valley near the Mill Run Reservoir in Fayette County, PA. This charismatic species (Arisaema triphyllum) is known as “Jack-in-the-Pulpit” and native to forests of the Eastern US. Its common name comes from its flowering structure – a distinctive hooded structure (spathe) that looks like a pulpit and the flowers (spadix) that resembles “Jack,” the minister standing within. This flower structure is shared among members of the arum family (Araceae; members often called “aroids”), which includes the popular houseplants known as “peace lilies.”
The natural history of Jack-in-the-pulpit is fascinating. For starters, individual plants can be male or female and the gender can switch from year to year! This species has intrigued botanists for decades and used as a study system to understand the ecology and evolution of plant sex expression. Larger plants tend to have female flowers, but the exact size is dependent on environmental conditions and genetics of a given population.
Jack-in-the-pulpit has calcium oxalate in its leaves that can irritate skin and is poisonous to ingest. It is generally avoided by deer. However, recent research from the lab of Susan Kalisz (Research Associate at the museum) has shown that deer overabundance negatively affects the growth of this species. While it is rarely eaten by deer, they affect other environmental conditions, such as light levels and soil conditions.
With over 870 specimens, this species is among the best replicated in the CM herbarium. However, there is some debate whether this species should be treated as multiple species or not.
Both of these specimens were collected on May 17 in Highland Park– but 50 years apart. John Bright collected the specimen on the left in 1952. Fifty years later to the day, Bonnie Isaac unknowingly recollected the same species in the same location!
If you look closely, you’ll notice the 1952 specimen did not yet produce seed by mid-May, while the 2002 specimen has already started developing the characteristic maple-like seeds. Due to increasing spring temperatures in recent decades, many plants tend to flower earlier, as shown through herbarium specimens. Botanists at the museum are studying the impacts of human-caused environmental changes over the past century by following in the footsteps of past collectors. We are revisiting field sites on the same day to compare modern day plants to specimens collected over 100 years ago.
Sycamore maple (Acer pseudoplatanus) is a common forest tree in Europe, where they simply call it “sycamore” but should not be confused with our native and introduced sycamores. Sycamore maple has been intentionally introduced across temperate regions, including the US and New Zealand. It has since become invasive, meaning it actively spreads across the landscape and can cause ecological damage. It is less common than other invasive maples (such as Norway maple) in this region, but is invasive in several sites in the Pittsburgh area.
Collected in 1908 (the first year Mother’s Day was celebrated!), this specimen was grown in cultivation at the former western headquarters for the Ferry-Morse Seed Company in Mountain View, California. The white carnation was chosen as a Mother’s Day symbol by Anna Jarvis, the holiday’s founder, because they were her mother’s favorite. Carnations remain closely associated with Mother’s Day in the United States, with white carnations traditionally as symbols in memory of mothers who have died and colored carnations to honor living mothers. The carnation, or Dianthus caryophyllus, is probably native to the Mediterranean, but its native range is obscured by at least 2,000 years of cultivation. There are over 27,000 named cultivars of Dianthus species.
Collected on May 6, 1950, this specimen was found in Bedford county, PA by Werner E. Buker. Buker was a math teacher at Perry High School, Pittsburgh and a long-time affiliate with the museum and the Botanical Society of Western PA.
This spring ephemeral has a great name: Dutchman’s breeches (Dicentra cucullaria). The white flowers look like little pants hung out on a line to dry. Bumblebees get nectar from this plant with the help of a long proboscis (tongue-like appendage).
Collected on May 4, 1928, this specimen was found in by Edward H. Graham in the Sonoran Desert of Mexico. Growing up to 60 feet tall, the Saguaro cactus (Carnegiea gigantea) is among the most iconic plants of the desert southwest. It is found in southwest Arizona and northern Mexico. Its distribution is strongly determined by freezing temperatures.
“Dippy” (Diplodocus carnegii) isn’t the only species named after Andrew Carnegie. In 1908, the Saguaro cactus was also named in honor of Andrew Carnegie, who funded early research in the cactus family.
How do you collect a cactus and press it to an herbarium sheet, you might ask? The answer: carefully. Sections are taken from the plant to include identifying features such as flower and spines. The spines are modified leaves, and unlike most plants, the stem is where photosynthesis happens. The fleshy stem (photosynthetic stem tissue) scooped out and salt can be used to help dry the specimen. The result can be quite artistic.
Saguaros can live upwards of 200 years old! Recent research has used the spines to reconstruct past climate conditions, and even aspects of plant physiology, using chemicals from the atmosphere (stable carbon isotopes) at the time the spine was produced. Because the newest spines are added to the top as the Saguaro grows in height, scientists can estimate how old each spine is.
This Saguaro specimen was collected during museum expedition in the spring of 1928. Specimens from this expedition helped in the design and construction of the Arizona Desert diorama in the Hall of Botany, which opened in the fall of 1929 and is just as cool to see today.
Collected on June 3, 1937 by J. Churchill in a vacant lot in Mt. Lebanon, this specimen is the oldest garlic mustard voucher for Allegheny county, Pennsylvania. Introduced to the U.S. in the late 1860s, garlic mustard (Alliaria petiolata) was a kitchen herb, but escaped gardens and is now a problematic weed in forests and roadsides across the eastern US.