Blackberries are a widely consumed fruit, but they represent a complex group of plants within the Rosaceae family. These fruits belong to the large and diverse Rubus genus, which also includes raspberries and dewberries. Botanically, the blackberry is not a true berry but an aggregate fruit, meaning it is composed of many small, individual sections called drupelets clustered around a central core. The fruit is distinguished from its close relative, the raspberry, because the central receptacle stays attached to the edible drupelets when the blackberry is picked, resulting in a solid core.
Primary Geographic Center of Origin
The evolutionary home of the Rubus genus is broadly centered across the temperate regions of the Northern Hemisphere. This extensive distribution suggests the genus is ancient and widespread, with multiple areas contributing to its initial diversification. Fossil evidence points toward a deep history, with Rubus fossils known from the Eocene-aged Florissant Formation in Colorado, dating back approximately 34 million years.
The genus expanded and diversified across Eurasia, North America, and other continents during the Miocene epoch. Therefore, blackberries originated and evolved simultaneously in both the Old World and the New World. This resulted in co-existing centers of diversity across the northern temperate zone, rather than a single point of origin.
Understanding Species Diversity and Native Ranges
The term “blackberry” refers not to one species, but to an immense complex of hundreds of closely related microspecies, primarily belonging to the Rubus subgenus Rubus. The taxonomy of this group is complicated due to frequent natural hybridization and a reproductive process called apomixis, where seeds are produced without fertilization. This complexity makes it difficult to clearly define species boundaries.
In the Old World, the European blackberry is often referred to as the Rubus fruticosus aggregate, a collection of numerous species found natively across Europe, northwestern Africa, and temperate western Asia. These European types have formed a dense web of micro-species, making their classification challenging. The New World species, native to North America, include well-known groups such as the erect Allegheny blackberry (Rubus allegheniensis) and trailing varieties known as dewberries, like the American dewberry (Rubus flagellaris).
From Wild Plants to Commercial Crops
For thousands of years, blackberries remained largely uncultivated, primarily harvested from wild stands in Europe and North America. Ancient Romans and Greeks utilized the wild fruit for medicinal purposes and food, but large-scale agricultural production was absent. Domestication began much later, with significant breeding efforts starting in the United States in the 19th century.
Plant breeders focused on selecting and hybridizing native species to create varieties suitable for commercial agriculture, such as higher yields and better fruit quality. This breeding work led to the development of thornless varieties and hybrid berries, like the Marionberry, which improved manageability and transportability. Today, the global commercial landscape is different from the original native ranges, with Mexico being the leading producer globally, followed by areas like the US Pacific Northwest and Chile.