It's the collective noun used in English to identify a group of martens.
See, A murder of crows, a gaggle of geese, and a frenzy of sharks
A group of martens is called a "richness."
Maria Martens was born in 1955.
Reiner Martens's birth name is Dirk-Reiner Martens.
Dr. Martens was created in 1947.
Martin Martens died in 1863.
Johan Martens was born in 1861.
Johan Martens died in 1932.
Ernesto Martens was born in 1933.
Martin Martens was born in 1797.
Hermann Martens was born in 1877.
Friderich Martens died in 1699.
Theodor Martens was born in 1822.