Millets Triangle – North American Millets Alliance

For visualizing millets as a group

The “Millets Triangle” – a North American Millets Alliance (NAMA) product – is an attempt to bring millets, broadly defined, into a single schematic that takes into account three key distinguishing factors:

their relative levels of production;
their botanical relationships; and
their geographic origins.

It was first designed in 2022 by NAMA’s Don Osborn, as a way of facilitating understanding of and teaching about this diverse group of mostly small-grained crops. The current design dates to 2024, and the current version is 3.1, dated 3 May 2025.

A full presentation of the Millets Triangle as a PDF of a PPT presentation is available for viewing or downloading. A brief description follows.

The Millets Triangle – common & scientific names

The Millets Triangle (Diversity of Millets in Global Perspective) is divided into cells – one for each millet – that are organized to the extent possible by the three distinguishing factors mentioned above. In the following two images, the cells carry first, English common names (it is recognized that these may vary), and second, the Latin scientific names (in the cases of pearl, browntop, and Guinea millets, there are alternate names).

The arrow on the left indicates that the vertical organization is (roughly) by level of grain production globally.

*Millets Triangle, with English common names*

Scientific names are binomial, formed with the name of the genus and the name of a species within that genus. Note in in the image below, that some genera (pl. of genus) appear more than once, and in those cases are in adjacent cells (with the sole exception of Setaria).

*Millets Triangle, with Latin scientific names* *(Genus species)*

The Millets Triangle – vertical ordering, explained

Here, the Millets Triangle is annotated to give a better idea how inclusion in each of its four levels is determined. The grain production levels of the 5 species in the top two levels are clearly higher than the rest. However, inadequate statistics make comparative placement of some of those in the lower levels difficult.

*The Millets Triangle, annotated to explain the vertical ordering*

The Millets Triangle – botanical relationships / groupings

The grain-bearing crop species we call millets are all in the family of grasses (Poaceae), along with the main cereals (wheat, rice, corn, barley, oats). However, millets are botanically quite diverse, being classified across two sub-families of Poaceae, five botanical tribes, and 12 genera.

Here, color-coding of the cells is used to illustrate these relationships/

*Millets Triangle, illustrating botanic diversity*

The Millets Triangle – geographical origins

Almost all the millets were domesticated either in some part of Asia, or some part of Africa. There are a very few exceptions, and in a few cases, early developments that may have spanned more than one continent. Nevertheless, to fully understand the diversity of millets, these various origins need to be considered.

In the Millets Triangle, millets originating in Asia are generally to the left, and those from Africa to the right. Color coding of cells is used here too.

*Millets Triangle, continental origins of millets*

The Millets Triangle – what’s grown in North America

Simple shading of cells is used here to illustrate the millets cultivated for diverse purposes in North America. A few are cultivated for grain (notably sorghum, proso, and teff), and all find other uses, including animal forage, as cover crops, and for wildlife.

*The Millets Triangle, showing millets currently grown in North America*

The Millets Triangle is free to use and modify, if you give credit and make your work sharable in the same manner. There are more examples of use of the Millets Triangle in the full presentation linked above.