Juncaceae
Leaf sheaths open; seeds numerous Juncus
Leaves terete (sometimes compressed) or reduced to sheaths with the lamina as a small acute tip to the sheaths
Lamina well developed, terete or ± compressed
Leaves jointed with internal septa (incompletely so in J. prismatocarpus); inflorescence rather loose, apparently terminal, with distinct clusters of flowers or individual flowers
Leaves 1 mm wide or wider, usually more than 3 flowers per cluster. Tufted plants usually more than 10 cm high
Cross septa incomplete, sometimes obscure. Leaves compressed. Perianth segments acute or acuminate, 3–4 mm long, shorter than the capsule. Stamens 3. Leaves up to 25 cm long. Widespread. Damp places Juncus prismatocarpus
Cross septa complete. Leaves terete