June 29, 1916: 102 years ago

Although often overlooked, herbarium specimens that were collected in cultivation have important uses. These plants were intentionally planted by humans rather than growing naturally in the wild.  These specimens were collected from farms, gardens, greenhouses, or even those planted in your yard or city parks.  These plant species are often economically important, providing benefits to humans in the form of food, medicine, fibers, or simply beauty.  The Carnegie Museum Herbarium has about 5,736 specimens that are known to be collected in cultivation, dating back to 1817!
 
This wheat (Triticum aestivum) specimen was collected on June 29, 1916 from a farm in Vallonia, Pennsylvania (Crawford County).  This specimen was collected well before the so-called “Green Revolution” of the 1930s-1960s when agriculture changed globally with new plant breeding technologies (high yielding crop varieties), increased pesticide use, and synthetic fertilizer production and use.  
 
Compare this particular wheat specimen (which barely fits on the herbarium sheet; note it is bent 3x to fit) to a much shorter one now on display in the We Are Nature: Living in the Anthropocene exhibit at the Carnegie Museum of Natural History. The specimen on display was collected nearly a 100 years later and is a dwarf variety.  This wheat cultivar was developed through plant breeding technologies in the mid-20th century to improve crop yields.  Semi-dwarf wheat was developed in Mexico in the 40s and 50s through plant breeding efforts led by Norman Borlaug, who later won the Nobel Peace Prize for his work that addressed world hunger through agricultural technologies.  The majority of the world's wheat crop is now a semi-dwarf variety.
 
Herbarium specimens collected in cultivation could provide important information on the types, traits, and genetics of crops grown over the past two centuries, a period of much change.  Are some disease-resistant genotypes or cultivars which no longer exist stored in herbaria? 
 
Another important, yet largely untapped, source of information in these specimens collected in cultivation is the non-native species planted intentionally for ornamental purposes.  Many of our non-native species which are now invasive and causing economic and ecological harm were first introduced intentionally for ornamental purposes. In many cases, information on some of the earliest introductions may be stored in herbaria.  These specimens are ripe for study.
 
Take oriental bittersweet (Celastrus orbiculatus) as an example.  Oriental bittersweet is a woody vine from East Asia, now a problematic invasive plant found throughout the Pittsburgh region and beyond.  It became particularly abundant in our region in the 1980s, now common to forests and roadside woods.  Interestingly, the oldest specimens collected in Allegheny County are not from the wild, but instead grown in cultivation in gardens.  Two specimens grown near Highland Park collected in 1916, followed by another specimen collected 34 years later (also in cultivation!).  It was not collected outside of a cultivated setting in the county until 1979.  And now, it is ubiquitous!  What insight can those first specimens collected in cultivation in 1916 tell us?  Were these the source of introduction? And more importantly, can they provide information on basic invasion processes to help us prevent future invasions by other species? 
 
Specimens collected in cultivation may be seen as “not natural” or otherwise less important than those collected in natural areas or found spontaneously growing without direct human intervention.  But it is clear that specimens collected from cultivation have an important role to play.  We must continue to record and archive cultivated species in natural history collections.  After all, human impact and the blurring of “nature” and “human-made” is the hallmark of the current era, the Anthropocene, so cultivated species document nature just the same way as “wild” occurring plants.