HEBERLING LAB

​Happy Halloween!
 
Collected on a spooky Halloween night in 1931 (well, it might have been during the day, but let’s just say night), this specimen was found by Curator of Botany Otto Jennings at Dixmont Hollow (near Emsworth), PA.  Witch hazel (Hamamelis virginiana) is a small deciduous tree found in forests and stream banks across the eastern US.  This awesome native plant is a notable for its fall flowering, with long ribbon-shaped bright yellow petals.  It flowers as the plant drops its leaves for fall, leaving branches with no leaves, but plentiful flowers.  Witch hazel is among the last plants in our region to flower in the fall.  As its fruit dry, it ejects the seeds, making a snapping sound.  
 
Why the name “witch hazel?”  Several explanations have been given. One is derivation from an old English word meaning “bendable.” More fitting for Halloween, another unverified claim is the plant was thought to be linked to witchcraft, both for its mysterious noises (snapping sounds during seed ejection) and supposed use in magic wands.

There’s a deeper evolutionary history behind jack-o-lanterns and pumpkin spice lattes than you might think.  Recent research from Penn State indicates the plant lineage might have went extinct had it not been for humans.  Species in the genus Cucurbita (including pumpkins, gourds, squashes) were domesticated by humans in eastern North America about 10,000 years ago.  That is, they were cultivated in gardens, likely first selected for the use of their durable rinds (anthropological evidence for gourds used as containers for drinking) and later as a food source.  Most Cucurbita species went extinct around this time, coinciding with the extinction of large mammals that these species relied upon to spread their seeds.  Their fruits were unpalatable to the smaller herbivores that did not go extinct. Ironically, it is human hunters, paired with climate change, that led to the extinction of large herbivores in North America.  Modern day pumpkins have adapted to the Anthropocene.

​Collected near Freedom (Beaver county, PA), this pumpkin specimen (Cucurbita pepo) was collected from Dun’s Farm in 1884 by John A. Shafer, who became the first Curator of Botany at the Carnegie Museum of Natural History a decade later.

​Over 90 years old and still beautiful color!  This red maple specimen was collected on October 23, 1926 by Otto Jennings during a field trip of the Botanical Society of Western PA to Chestnut Ridge in the beautiful Laurel Highlands of Pennsylvania.  Red maple (Acer rubrum) is one of the most common trees in eastern North America.  You can find it from southern Canada down to Florida and Minnesota down to eastern Texas. And it is renowned for its beautiful scarlet red foliage in autumn.  Happy fall!  

Kudzu is one of the more well-known weeds, at least by name, sometimes known as “the vine that ate the South.”  Collected on October 13, 1997, this specimen was found by Sue Thompson and Bonnie Isaac near the I-376 Squirrel Hill tunnel, Pittsburgh. Kudzu (Pueraria lobata) was introduced to the US as an ornamental in 1876 at the Centennial International Exhibition in Philadelphia.  The vine was initially prized in the South to provide shade.  The vine was later promoted for use in erosion control.  Although listed as a noxious weed in PA, it is more invasive in southern states.  There, it has been estimated to spread at a rate of 2,500 acres per year (some say up to 150,000 acres per year, although this estimate has been questioned).  Infestations of this plant undoubtedly causes ecological and economic damage.
 
Below is another specimen of kudzu, collected in its native range in Japan in 2002.  Although plants are collected in both native and invasive ranges, few studies have compared specimens of the invasive species across continents.

​Nancy Hanks Lincoln (mother of Abraham Lincoln) died on Oct. 5, 1818 from “milk sickness.”  Milk sickness is caused by poisoning after drinking milk from cows that have eaten the plant white snakeroot (Ageratina altissima).  Also known as “puking fever” or simply “the trembles,” early European-American settlers in the Midwest initially thought milk sickness was an infectious disease.  It was soon realized that the unidentified illnesses were caused by drinking milk from cows that ate white snakeroot, which contains the chemical tremetol, a toxin which causes weakness, pain, vomiting, abdominal pain, and can lead to coma and death.  The cattle of these early settlers often wandered into the forest to graze, seeking additional forage outside limited pastures.  However, milk sickness is very uncommon today due to modern farming practices and cows rarely have access to eat this plant.
 
White snakeroot is a fall blooming, shade-tolerant species found in forests across the Eastern US, and commonly found throughout southwestern PA.  This specimen pictured was collected in 1998 in southwestern Indiana, about 90 miles north of the Little Pigeon Creek Community, where Abraham Lincoln’s family lived.

Another fall blooming aster!  ​Collected on October 6, 1896 (same year Carnegie Museum was founded!), this specimen was found by early museum botanist John Shafer on Jack’s Island, a small island on the Allegheny River (between Harrison Twp and city of Lower Burrell).   Despite the name, New England aster can be found across eastern North America.  Along with many other species in the genus Aster, this species was recently reclassified in the Symphyotrichum genus.  Symphyotrichum novae-angliae is a perennial (lives for several years) with beautiful deep blue-purple flowers.  Like other plants in the sunflower family (Asteraceae), the “flowers” are actually a cluster of flowers (heads) composed of many flowers, with “ray” and/or “disk” flowers.