In fact, even as some would-be harvesters continue to find their way to the patches of wild cannabis, authorities have largely backed away from seeking and destroying ditch weed — partly because of funding cuts and a focus on more sinister drugs, but also because getting rid of the plants is seen as an impossible task.
“We respond to it as we’re able. Do we have people out there searching for ditch weed? No. Generally, our efforts are concentrated on marijuana that’s being potentially cultivated.”
“Today we still make arrests in those cases and have instances where those plants are still being picked, and it is a concern,” said a state police marijuana eradication supervisor who asked not to be named because he conducts undercover investigations.
The researchers also found that this so-called basal lineage of cannabis split off from the more heavily domesticated varieties grown today about 12,000 years ago, and that the psychoactive and fibrous strains of cannabis didn’t diverge from one another until about 4,000 years ago. This places the initial stages of cannabis’ domestication in a time and place that is already known as a hotbed of agricultural innovations—where modern crops including rice, broomcorn and foxtail millet, soybean, foxnut, apricot and peach were launched.
Page also notes that the current study is based only on living samples, and that drawing on dried plant materials preserved in herbarium collections could provide a source of old and rare varieties. “There’s a whole other dimension to be explored there, but the onus is on us as a research community to extend the work,” says Page.
“If you wanted to make a world map of where all the genetic pieces of cannabis come from, this paper shows us where all the weird and wild stuff is,” says Jonathan Page, a plant biologist at the University of British Columbia who was not involved in the work.
Whether you think it’s the devil’s lettuce, nature’s medicine or a conduit to the divine, cannabis and humans have a relationship stretching back thousands of years that has now spawned hundreds of varieties. But millennia of cultivation, breeding and the plant’s relatively recent status as a cultural taboo have obscured where exactly cannabis went from being a wild weed to being picked up by humans and put on a path toward becoming the multi-billion-dollar crop it is today.
Armed with this trove of genetic information, the team analyzed the genomic data to figure out the evolutionary relationships among these cannabis plants from around the world. The analysis revealed that a group of feral plants hailing from East Asia are more closely related to cannabis’ wild ancestors than any of the varieties grown today for fiber or medicine and recreation.
These roadside plants, sometimes referred to as “ditch weed” in the United States, may look wild but they’re more accurately classified as feral. Despite propagating without direct human assistance, DNA analysis shows these upstarts are descended from escaped domesticated plants. Because the species is wind pollinated, these escapees can readily mix with any other nearby cannabis plants. In some locations this would have set up a scenario in which domestic escapees likely swapped genes with their undomesticated ancestors, potentially diluting or even, in a slightly Oedipal turn, eliminating truly wild cannabis. This, on top of continuous artificial selection and intentional hybridization by farmers and breeders as well as the plant’s still-checkered legal status, which hamstrung research for decades, has made the tale of cannabis’ origins a tangled one.
Though the third lineage uncovered by the study is more closely related to cannabis’ wild ancestors than any of the drug or fiber varieties grown today, these basal cannabis varieties all appear to be feral rather than truly wild—meaning humans had some hand in guiding the plants’ evolution. This, along with the sheer number of genomes they sequenced, led Fumagalli and his co-authors to the somber conclusion that the pure wild progenitors of cannabis are probably extinct.