How are sedge leaves arranged differently from grass leaves?

Sedge leaves differ from grass leaves primarily in their arrangement and the structure of their sheaths:

• Leaf Arrangement: Grasses exhibit distichous phyllotaxy, meaning their leaves are arranged alternately in two vertical rows on opposite sides of the stem. In contrast, sedges exhibit tristichous phyllotaxy, where leaves are arranged in three vertical rows, with each successive leaf developing at 120-degree intervals around the stem.1
• Sheath Structure: In grasses, the leaf margins grow around the stem and overlap. In sedges, the leaf margins fuse when they meet on the side of the stem opposite the center of initiation, creating a closed sheath.1