stump (of a tree) / strain / root / origin / founder

pureblooded, native (of many generations standing, of impeccable pedigree)

(figuratively) to hive off, to spread, to produce offspring, to start a line of descendants, to found a family, to establish a colony (somewhere)

stem cell

(linguistics) root (word from which another word or words are derived)

a Frenchman of old stock

(figuratively) to sleep like a log

Souchez (a town in the Pas-de-Calais department, Hauts-de-France, France)

plant of the genus Cyperus / Ellipsis of souchet comestible. (Cyperus esculentus); chufa

plural of souchet