Dulichium is usually placed in Scirpeae tribe of Cyperaceae, though it is rather isolated there. Unlike any other member of that tribe, it has flat spikelets due to arrangement of scales in two rows. (Other members have spirally arranged scales). Flattened spikelets are sessile in two ranks on peduncles developing from leaf sheaths. Three-way sedge is so special that some prefer to place it separately, in its own monotypic tribe Dulichieae.