To these the semi-sedentary Arabs who sparsely cultivate the river valley, dwelling sometimes in huts, sometimes in caves, pay a tribute, called kubbe, or brotherhood, as do also the riverain towns and villages, except perhaps the very largest.
The only riverain towns of any importance on this stretch of the river to-day are Samsat, Birejik, Deir, `Ana and Hit.
The principal products are millet, sesamum and sugar produced from toddy-palms in the riverain districts, which also grow rice, grain, peas and beans.
The province is mainly a mountainous region, but includes the Peshawar valley and the broad riverain tract of the Indus in Dera Ismail Khan district.
They speak a purer Arabic than the riverain tribes.