Carex atrata

About

Carex atrata, called black alpine sedge, is a widespread species of flowering plant in the genus Carex, native to Greenland, Iceland, and most of Europe, plus scattered locations across temperate Asia, including Anatolia, Siberia and the Himalaya, as far as Taiwan and Japan. Its chromosome number is 2n=52, with some variants reported, e.g. n2=54 for Greenland material.

Summary from Wikipedia