If you do a search on "is sorghum a millet?" you'll likely come up with a
negative response that pivots on sorghum (Sorghum bicolor) being
botanically (taxonomically) more closely related to corn than it is to
other millets. The larger botanical picture, however, is more complicated.
Also, we also know that outside of North America especially, many consider
sorghum among the millets - it was included in the International Year of
Millets (2023) and is NAMA's millet-of-the-month in June.
What is the case for including sorghum among the millets?
On the botanical side, I've pointed out previously that while it is true
that sorghum, like corn, is in the Andropogoneae tribe,/1 so too are adlay
(Coix lacryma-jobi) and the rare but interesting Taiwan oil millet
(Spodiopogon formosanus). Moreover, there are two other millets that are in
an entirely different sub-family of Poaceae (the botanical grass family
that includes all grains) - namely finger millet (Eleusine coracana) and
teff (Erogrostis tef). WHich is to say, that they are more outliers than
the Andropogoneae group. So, the botanical / taxonomic argument that
sorghum should not be considered a millet doesn't really hold up. If we are
to draw line between millets and not millets, it can't be solely on the
basis of taxonomic proximity./2
The category of "millets" is in some ways a "folk taxonomy," largely shaped
by history, culture, and language. So where does sorghum fall in these
respects? Among its common names historically have been "great millet,"
"Indian millet," and "Egyptian millet" (although for the latter two it's
possibly more complicated). On the other hand, it has also been called
"Guinea corn," and one variety, "broomcorn" (the term "broomcorn millet" as
I understand it, then compares proso millet - Panicum miliaceum - back to
sorghum, based on the use obvious in the names). For some years, I've seen
sorghum and pearl millet (Pennisetum glaucum / Cenchrus americanus)
grouped as "major millets" as opposed to the many "minor millets" or "small
millets" which as a general rule, have their grains in hard hulls./3 In
these respects, it seems hard to separate sorghum out from the millets.
In terms of production and extent of cultivation, sorghum is in a class by
itself. The volume of grain sorghum harvested is roughly twice that of all
other millets combined. On the other hand, its production is about a tenth
of that of any of the major cereal grains.
In terms of water use, it is comparable to many of the millets - which is
to say, it needs less to produce than major cereal grains./4
In terms of marketing and consumer acceptance as food in North America,
sorghum faces similar challenges to those of other millets.
The latter is, for me, the most important consideration for NAMA continuing
to include sorghum among the millets. At the same time, since sorghum in
the US has an important, funded infrastructure for its promotion as a crop
and food, we don't need to spend as much of our limited time and resources
on promoting it.
Ultimately, however, we don't need a debate on whether sorghum is or isn't
a millet (maybe both are true?). My personal perspective is that sorghum
and each of the other millets are individual grains that can play more
important roles in our agriculture and food cultures. The category of
millets, even if it might be a bit more fluid and even contested at its
margins, facilitates our discussion of all of them in the future of food
and ag.
Notes:
1. Botanical hierarchy: … > Family > Sub-family > Tribe > Genus > Species
2. On the other hand, the more recent inclusion by some in India of certain
pseudo-cereals - notably amaranth and buckwheat - among the millets goes
too far, in my opinion. These are in an entirely different botanical family.
Some have also used the term "pseudo-millets," but this term is not
generally accepted, and in any event, is redundant to the accepted term of
pseudo-cereals
3. Finger millet is an interesting exception, and in some recent
literature, it is grouped among the "major millets."
4. Proso millet and pearl millet, however, are the most adapted of all the
millets to hot and dry conditions.
Don Osborn, PhD
(East Lansing, MI, US)
North American Millets Alliance
