HEBERLING LAB

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
 

Put that in your pipe and smoke it!
Well, please don’t, really. This is a scientific specimen.
 
This tobacco specimen was collected in Ecuador by Hendrik Balslev on February 21 1984. Hendrik Balslev is now a professor at Aarhus University, Denmark, who studies the taxonomy and ethnobotany of plants of the Amazon. This specimen was planted by the Secoya tribe in the “area of tropical rainforest.” The Secoya are a group of indigenous peoples, with a distinct culture and language, living in the Amazon regions of Ecuador and Peru.
 
Tobacco refers to more than 70 species of plants in the genus Nicotiana. In the nightshade family (Solanaceae), tobacco is related to deadly nightshade, potatoes, and tomatoes. They famously contain the addictive alkaloid stimulant chemical nicotine. Nicotine is a neurotoxin for insects, produced by plant for its insecticide properties.  For that reason, tobacco has also been used as an insecticide.
 
Tobacco is a culturally important plant, far beyond a pack of cigarettes. The commonly cultivated species is Nicotiana tabacum. Tobacco has rich, long history of medicinal and traditional use in the Americas, especially Mesoamerica and Caribbean, and with many native American tribes growing and using tobacco for centuries. It was used for smoking, in religious ceremonies, socially, as a sign of peace (peace pipes), as a good for trade, and more. There is evidence suggesting its cultivation in Mexico as early as 1500 BC.
 
When Europeans arrived in the Americas, tobacco was quickly prized and popularized in Europe.  Tobacco was influential in European colonization in North America, becoming a major cash crop. Tobacco was important to the history of the United States, but with a dark side. Many of America’s founding fathers had tobacco plantations, mostly operated through slave labor. The cultivation of tobacco fueled the early slave trade in 17th and 18th century America.  The number of slaves from Africa in the Chesapeake region (Virginia) and North Carolina increased greatly.   
 
A complicated plant – botanically and culturally.
 
Find this specimen and more here: http://midatlanticherbaria.org/portal/collections/list.php?db=328&catnum=CM321082&othercatnum=1

Perhaps not the most beautiful specimen in the collection, but check out the prickly stem! Former Carnegie Museum curator Otto Jennings described this species as “an obnoxious weed of farmlands and waste places” (1953).  This leafless specimen of Carolina nightshade (Solanum carolinense) was collected on November 9, 1915 in “Pittsburgh district” by Frank R. Alker. Carolina nightshade (also called horse nettle, wild tomato, and many other names) is in the potato/tomoato family (Solanaceae).  It is commonly found in disturbed and anthropogenic (human-made) environments, such as those in cities. 
 
Horse nettle is native to the Southeastern US, and now widely distributed as a naturalized species across the world. Although native to parts of the US (probably including PA), it is considered a noxious weed in some states.
 
This specimen is available virtually online at http://midatlanticherbaria.org/portal/collections/individual/index.php?occid=12257516&clid=0

 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
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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.