For most of the twentieth century, cacao (Theobroma cacao) was described with a simple three-way model: Criollo, Forastero, and Trinitario. Criollo stood for the rare, mild, aromatic cacao of early Mesoamerican cultivation; Forastero for the hardy, high-yielding Amazonian cacao behind most of the world crop; and Trinitario for hybrids between the two. The model was easy to teach and is still widely repeated, but it is an oversimplification.

The main problem is that "Forastero" was never a real biological group. It was a catch-all label for everything that was not Criollo, and it concealed most of the species' actual diversity. The wild and semi-wild cacao of the Amazon basin is far more varied than a single category can express, and treating it as one type made that variation invisible.

Motamayor et al. (2008) addressed this directly. Using molecular markers across a broad collection of cacao germplasm, they reclassified the species into ten genetic clusters: Criollo, Amelonado, Contamana, Curaray, Guiana, Iquitos, Marañón, Nacional, Nanay, and Purús. Most of these clusters correspond to regions of the upper Amazon, the centre of the species' diversity. In this framework Criollo remains one cluster, Amelonado (the low-diversity lower-Amazon population spread historically to West Africa) is another, and the bulk of what was once "Forastero" is distributed across the remaining Amazonian groups.

This reframing also clarifies two names that are often misunderstood. Trinitario is not a genetic cluster at all. It is a family of hybrid populations descended from crosses between Criollo and Amazonian cacao, first arising on Trinidad, and it is genetically variable rather than uniform. CCN-51, similarly, is a single bred clone — a hybrid selected in Ecuador for yield and disease tolerance — not a cluster and not a traditional type. "Nacional" is genuinely a cluster in the Motamayor scheme: the western-Amazon group associated with the floral arriba cacao historically grown in Ecuador.

A modern archive should use the cluster framework rather than the three-way model because it reflects the actual structure of cacao diversity, distinguishes populations from hybrids and clones, and gives a stable, evidence-based vocabulary for describing origins. The older terms are not banned — they remain useful shorthand and appear constantly in trade — but they should be understood as historical and commercial categories, not genetic ones.

This is reference material in an early-stage archive; corrections are welcome.