Bronze Age cannabis seeds illuminate cultivation at Haimenkou

More than 800 charred cannabis grains from Haimenkou, a Bronze Age settlement in Yunnan, provide evidence for studying the plant within an agricultural community. A paper first published online in November 2023 examined their measurements and compared them with cannabis material from other times and places.

An excavated crop assemblage

The remains came from the 2008 excavation. The assemblage spans contexts dated between approximately 1650 and 400 BCE, with about 700 cannabis grains concentrated in one context dated to 1400–1100 BCE.

Rita Dal Martello and colleagues measured 30 cannabis grains. Keeping that figure separate from the total recovered avoids suggesting that every grain underwent the same detailed analysis. Charred remains also require attention to preservation when their dimensions are compared with modern or differently preserved material.

What seed size can suggest

The authors compared archaeological measurements with modern examples associated with different uses. Most Haimenkou measurements occupy a range shared by fibre or oilseed plants and psychoactive types. Overlap prevents a simple identification of the crop’s intended purpose.

A measured seed is consequently evidence with limits. The study does not demonstrate the THC content of the plants, identify a particular medicine, or establish that residents smoked cannabis. Nor does the absence of such proof make the material irrelevant to cannabis history: cultivation and crop diversification are historical questions in their own right.

Alongside genetic research

The authors discuss the 2021 genomic domestication study, which inferred an early East Asian history from modern plants. The two approaches observe different things. Genomes can support models of relationships between populations; excavated grains preserve material in dated settlement contexts.

Treating them together helps separate an inferred early origin from a particular archaeological occurrence. Neither the ancient age of the species nor a proposed domestication date supplies the intended use of every later crop.

Dating the discovery in the timeline

The journal article belongs to a 2024 volume, but its first online publication was 30 November 2023. That is the date used for this research event. The excavation year and Bronze Age context dates remain explicit in the account.

The entry adds agricultural history to the record for China. It presents cannabis as a plant studied among settlement crops, while leaving unresolved how much was grown for seed, fibre, medicine or other purposes. A broad history of cannabis needs room for that uncertainty alongside better-known evidence of intoxication.^[1][2]