Schoenus submarginalis is a species of sedge endemic to the mountains of the Western and Eastern Cape provinces of South Africa.

It appears that part of this problem is caused by the tendency of the southern African Schoenus to form hybrids with each other.

[1] Other notable genera in tribe Schoeneae include Lepidosperma, Oreobolus, Costularia, Tetraria and Gahnia.

[1] Southern African Schoenus were once classified as Tetraria; however, based on molecular and morphological differences, we now know that the two groups are evolutionary distinct.

[1] Its distribution ranges from Aynsberg in the west to the Baviaanskloof area in the east, growing at elevations over 600 m on coarse substrates.