The main distinguishing characters of S. graminifolius are its papery (chartaceous) spikelet glumes that have reddish-purplish streaking throughout.

[1] Schoenus auritus also has lower primary inflorescence bracts that are widened at the base; however, that species has firmer glumes.

[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.

[5] Schoenus graminifolius has been found growing on granitic soils at elevations greater than 120 m.[1] To date, it is only known from the Cape Peninsula.