Men and women harvest the Ethiopian staple grain teff in a roadside field between Axum and Adwa in Northern Ethiopia.

According to Wikipedia:

Teff or taf (Eragrostis tef, Amharic ṭēff, Tigrinya ṭaff) is an annual grass, a species of lovegrass native to the northern Ethiopian Highlands of northeastern Africa.

It has an attractive nutrition profile, being high in dietary fiber and iron and providing protein and calcium.

It has a sour taste. It is similar to millet and quinoa in cooking, but the seed is much smaller.

Teff is an important food grain in Ethiopia and Eritrea, where it is used to make injera . . . (It is now raised in the USA, in Idaho in particular.)

Because of its small seeds (less than 1 mm diameter), one [person] can hold enough to sow a large area in one hand. This property makes teff particularly suited to a seminomadic lifestyle.

The word "tef" is connected by folk etymology to the EthioSemitic root "ṭff", which means "lost" (because of the small size of the grain).