Cyperus papyrus

C. papyrus is a large, emergent, aquatic perennial, producing short rhizomes covered in thick, black scales. The roots are tough, extending 1 m or more in suitable substrate. Rootlets are numerous. Culms are erect, up to 5(-9) m tall, 5-6 cm or more (15 cm or more;Ludwig Triest, personal observation, 2015) across at the base (widest point), smooth, trigonous (angles very rounded, particularly on lower parts) and green (photosynthetic), spreading when old. The pith is solid, white-light brown;vascular bundles prominent. Leaves are reduced, sheathing and restricted to the basal 50 cm or so of the culms. They are tough, reddish-blackish brown when young, expanding with age, the coloration restricted to lateral edges sub-marginally;margins scarious, becoming papery. Colours fade and sheaths split ventrally with age.