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Amateur birdwatcher, botanist, entomologist, interested in herbology and agriculture. All round nature lover. Longform content: https://t.co/JYaifF8ln7

Aug 17, 2023, 30 tweets

Millets of the world, part: the last. As a final homage to the breathtaking diversity of millets, this thread will be a grab bag of short segments dedicated to the most notable (subjectively) species remaining on the list. Expect the unexpected for this one


Previous thread on finger millet here:

First on our list, Sonoran millet, or Panicum sonorum, will also serve as a teaser into what is enticingly called the “Lower Sonoran Agricultural Complex”, the richest assemblage of crop diversity North of Mexico, located in the Sonoran desert astride the US-Mexico border

There is some confusion here as some of the crops in the complex are described as cultivated but not domesticated, meaning seeds were repeatedly gathered in the wild and grown for the purpose of consumption without any attempt at controlled breeding

The region is particularly rich in wild millet species of the Panicum genus, such as common arid climate annuals P. arizonicum, P. capillare, P. hirticaule, … but also perennial species like P. obtusum and P. urvilleanum (used as food by the Hopi & Cahuilla, respectively)

Many of these species are close, being classified in succession as species, subspecies, mere local varieties… P. sonorum, described as being eaten by the Cocopa natives, was suggested by some to be a cultivated form of P. hirticaule because of its particular proportions

P. sonorum grows in floodplains, open woodlands and ravines where it forms large monospecific stands, it also readily colonises disturbed habitats such as roadsides and areas near villages. It has a very high forage value and is appreciated by farmers

It is a very restricted endemic crop which was not cultivated in neighbouring Mesoamerica, despite being present in the wild from Arizona to Honduras or in the Mississippi valley which possessed its own agricultural complex

Around the Colorado river, seeds were planted by men in areas where it had carved out muddy floodplains filled with nutritious silt for the crops. A magic ritual encouraged the river to flood the right areas, and the crops required little maintenance although planting was arduous

By the mid 20th century this small scale cultivation along the river banks had been abandoned, mainly because damming and ecosystem alterations prevented the river from forming the floodplains where the grass most easily grew. About 2000 Cocopa still live today in AZ and Cali

Next up is a weird little plant called Spodiopogon formosanus, which was exclusively cultivated on the island of Taiwan, especially in the highlands, by the ancestors of the Austronesians. It has no vernacular name, being called by default Taiwan millet

Today it’s cultivated on a small scale by Paiwanese farmers in high altitude villages. They rarely eat it, but grow it in isolated corners to renew their seed reserves and sell part of them. It’s scarcely grown because it’s hard to process and the plant’s hairs irritate the skin

One of the most obscure crops found today, little is known about its history or domestication, although it possesses traits of limited seed-dispersal typical of domesticated cereals. Its wild ancestor may have been S. cotulifer, native to Taiwan and China

Digitaria sanguinalis, known as crabgrass, is a ubiquitous “weed” present in most countries. Its fast growth, smothering of competing plants, high seed production and resistance to heat and drought allow it to colonise a wide range of habitats, especially fields

Digitaria are some of the earliest domesticated plants, although they were abandoned in historical times in favour of maize and wheat varieties. These extremely rugged plants owe their name to the arrangement of their floral spikes which look a bit like a hand

It was grown in central & Eastern Europe during the Middle-Ages, under the name manna, its grains being highly nutritious and its grass being an excellent fodder for livestock. It was even transported to the USA by immigrants from this region for these purposes

The earliest written records date to the 14th century, but could refer to both crabgrass and various plants of the Glyceria genus. Manna was still widely known and consumed until at least the 19th century

A major drawback is that the plant produces seeds continuously all summer, meaning it has to be harvested by hand, as multiple passes with mechanical harvesters would be require and much of the grain would be wasted

Today, it is a feralised, difficult to deal with weedy plant which can significantly affect yields of many crops such as beans, bell peppers or other cereals and is actively being studied in order to discover ways to limit its vigorous capacity for growth and survival

A final crop for today will be Panicum sumatrense, the “little millet” from India, a country with a long and storied love affair with these types of grains. Its wild ancestor is P. psilopodium, with which it hybridizes into a crop weed with poor yield

Two varieties are known, P. sumatrense “nana” is grown throughout India and South Asia, remaining prostrate until flowering time at which point they form an erect, large and open inflorescense. “Robusta” is only known in the Eastern Indian Ghats and always grows erect

While it has not been found in the archaeological record, it’s been suggested its wide adoption by many different tribes all throughout India betrays an ancient presence on the subcontinent. It is a fast growing plant that reaches full maturity 90 days after sprouting

It’s most often cultivated by populations from hilly areas, where it’s the main cereal. Irrigation and plowing are used in the valleys, while slash-and-burn was only replaced recently in the hills by continuous cultivation due to population pressure

Millets are typically sown in pairs instead of monocultures, with a major crop (usually sorghum, pearl or finger millet) supplemented by a minor one sowed over it (foxtail, kodo millet or little millet) which are harvested at different times of the year

There is a theory that this fast-growing and extremely adaptative crop (able to grow on even the poorest land) is secondarily domesticated, being first a weed of fields or rice paddies which was eventually incorporated into the food banks

At the end of the day, we see through this dizzying diversity of species that the term millet may be one of the most ambiguous in agriculture today, being essentially a wastebasket term for a wide variety of ancient and abandoned, or locally cultivated, cereals

They show us that plant domestication may have been an extremely iterative process that was tried on a wide variety of species, some of which may have been lost to time altogether. Like tools, humans chose the crops best adapted to their local conditions

In a world where the selection of food has never been wider for the average westerner, the variety of cultivated plants has gone down with the advent of mechanization and the superiority of wheat and maize in the current agricultural system

However these old tools of ours, all these near-forgotten millets, are still available to us if a time ever comes where we need to radically rethink our agriculture to be more harmonious with local conditions and less dependent on external inputs and mechanized strategies

In the meantime, the only thing to be done is keep that knowledge alive and maintain these orphan crops in their current ranges, so we know where to find them if they’re ever needed

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